File indexing completed on 2024-05-12 16:01:40

 /*
  *  SPDX-FileCopyrightText: 2005-2007 Cyrille Berger <cberger@cberger.net>
  *
  *  SPDX-License-Identifier: GPL-2.0-or-later
  *
  */
 
 #include "kis_png_converter.h"
 // A big thank to Glenn Randers-Pehrson for his wonderful
 // documentation of libpng available at
 // http://www.libpng.org/pub/png/libpng-1.2.5-manual.html
 
 #ifndef PNG_MAX_UINT // Removed in libpng 1.4
 #define PNG_MAX_UINT PNG_UINT_31_MAX
 #endif
 
 #include <KoConfig.h> // WORDS_BIGENDIAN
 #include <KoStore.h>
 #include <KoStoreDevice.h>
 
 #include <limits.h>
 #include <stdio.h>
 #include <zlib.h>
 
 #include <QBuffer>
 #include <QFile>
 #include <QApplication>
 
 #include <klocalizedstring.h>
 #include <QUrl>
 
 #include <KoColorSpace.h>
 #include <KoDocumentInfo.h>
 #include <KoID.h>
 #include <KoColorSpaceRegistry.h>
 #include <KoColorProfile.h>
 #include <KoColor.h>
 #include <KoUnit.h>
 
 #include "dialogs/kis_dlg_png_import.h"
 #include "kis_clipboard.h"
 #include "kis_undo_stores.h"
 #include <KisDocument.h>
 #include <KoColorModelStandardIds.h>
 #include <kis_config.h>
 #include <kis_cursor_override_hijacker.h>
 #include <kis_group_layer.h>
 #include <kis_image.h>
 #include <kis_iterator_ng.h>
 #include <kis_layer.h>
 #include <kis_meta_data_backend_registry.h>
 #include <kis_meta_data_store.h>
 #include <kis_paint_device.h>
 #include <kis_paint_layer.h>
 #include <kis_painter.h>
 #include <kis_transaction.h>
 
 #include <kis_assert.h>
 
 namespace
 {
 
 int getColorTypeforColorSpace(const KoColorSpace * cs , bool alpha)
 {
 
     QString id = cs->id();
 
     if (id == "GRAYA" || id == "GRAYAU16" || id == "GRAYA16") {
         return alpha ? PNG_COLOR_TYPE_GRAY_ALPHA : PNG_COLOR_TYPE_GRAY;
     }
     if (id == "RGBA" || id == "RGBA16") {
         return alpha ? PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB;
     }
 
     return -1;
 
 }
 
 bool colorSpaceIdSupported(const QString &id)
 {
     return id == "RGBA" || id == "RGBA16" ||
         id == "GRAYA" || id == "GRAYAU16" || id == "GRAYA16";
 }
 
 QPair<QString, QString> getColorSpaceForColorType(int color_type, int color_nb_bits)
 {
     QPair<QString, QString> r;
 
     if (color_type ==  PNG_COLOR_TYPE_PALETTE) {
         r.first = RGBAColorModelID.id();
         r.second = Integer8BitsColorDepthID.id();
     } else {
         if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
             r.first = GrayAColorModelID.id();
         } else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA || color_type == PNG_COLOR_TYPE_RGB) {
             r.first = RGBAColorModelID.id();
         }
         if (color_nb_bits == 16) {
             r.second = Integer16BitsColorDepthID.id();
         } else if (color_nb_bits <= 8) {
             r.second = Integer8BitsColorDepthID.id();
         }
     }
     return r;
 }
 
 
 void fillText(png_text* p_text, const char* key, QString& text)
 {
     p_text->compression = PNG_TEXT_COMPRESSION_zTXt;
     p_text->key = const_cast<char *>(key);
     char* textc = new char[text.length()+1];
     strcpy(textc, text.toLatin1());
     p_text->text = textc;
     p_text->text_length = text.length() + 1;
 }
 
 long formatStringList(char *string, const size_t length, const char *format, va_list operands)
 {
     int n = vsnprintf(string, length, format, operands);
 
     if (n < 0)
         string[length-1] = '\0';
 
     return((long) n);
 }
 
 long formatString(char *string, const size_t length, const char *format, ...)
 {
     long n;
 
     va_list operands;
 
     va_start(operands, format);
     n = (long) formatStringList(string, length, format, operands);
     va_end(operands);
     return(n);
 }
 
 void writeRawProfile(png_struct *ping, png_info *ping_info, QString profile_type, QByteArray profile_data)
 {
 
     png_textp      text;
 
     png_uint_32    allocated_length, description_length;
 
     const uchar hex[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
 
     dbgFile << "Writing Raw profile: type=" << profile_type << ", length=" << profile_data.length() << endl;
 
     text               = (png_textp) png_malloc(ping, (png_uint_32) sizeof(png_text));
     description_length = profile_type.length();
     allocated_length   = (png_uint_32)(profile_data.length() * 2 + (profile_data.length() >> 5) + 20 + description_length);
 
     text[0].text   = (png_charp) png_malloc(ping, allocated_length);
     memset(text[0].text, 0, allocated_length);
 
     QString key = QLatin1Literal("Raw profile type ") + profile_type.toLatin1();
     QByteArray keyData = key.toLatin1();
     text[0].key = keyData.data();
 
     uchar* sp = (uchar*)profile_data.data();
     png_charp dp = text[0].text;
     *dp++ = '\n';
 
     memcpy(dp, profile_type.toLatin1().constData(), profile_type.length());
 
     dp += description_length;
     *dp++ = '\n';
 
     formatString(dp, allocated_length - strlen(text[0].text), "%8lu ", (unsigned long)profile_data.length());
 
     dp += 8;
 
     for (long i = 0; i < (long) profile_data.length(); i++) {
         if (i % 36 == 0)
             *dp++ = '\n';
 
         *(dp++) = (char) hex[((*sp >> 4) & 0x0f)];
         *(dp++) = (char) hex[((*sp++) & 0x0f)];
     }
 
     *dp++ = '\n';
     *dp = '\0';
     text[0].text_length = (png_size_t)(dp - text[0].text);
     text[0].compression = -1;
 
     if (text[0].text_length <= allocated_length)
         png_set_text(ping, ping_info, text, 1);
 
     png_free(ping, text[0].text);
     png_free(ping, text);
 }
 
 QByteArray png_read_raw_profile(png_textp text)
 {
     QByteArray profile;
 
     static const unsigned char unhex[103] = {
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 11, 12,
         13, 14, 15
     };
 
     png_charp sp = text[0].text + 1;
     /* look for newline */
     while (*sp != '\n')
         sp++;
     /* look for length */
     while (*sp == '\0' || *sp == ' ' || *sp == '\n')
         sp++;
     png_uint_32 length = (png_uint_32) atol(sp);
     while (*sp != ' ' && *sp != '\n')
         sp++;
     if (length == 0) {
         return profile;
     }
     profile.resize(length);
     /* copy profile, skipping white space and column 1 "=" signs */
     unsigned char *dp = (unsigned char*)profile.data();
     png_uint_32 nibbles = length * 2;
     for (png_uint_32 i = 0; i < nibbles; i++) {
         while (*sp < '0' || (*sp > '9' && *sp < 'a') || *sp > 'f') {
             if (*sp == '\0') {
                 return QByteArray();
             }
             sp++;
         }
         if (i % 2 == 0)
             *dp = (unsigned char)(16 * unhex[(int) *sp++]);
         else
             (*dp++) += unhex[(int) *sp++];
     }
     return profile;
 }
 
 void decode_meta_data(png_textp text, KisMetaData::Store* store, QString type, int headerSize)
 {
     dbgFile << "Decoding " << type << " " << text[0].key;
     KisMetaData::IOBackend *exifIO = KisMetadataBackendRegistry::instance()->value(type);
     Q_ASSERT(exifIO);
 
     QByteArray rawProfile = png_read_raw_profile(text);
     if (headerSize > 0) {
         rawProfile.remove(0, headerSize);
     }
     if (rawProfile.size() > 0) {
         QBuffer buffer;
         buffer.setData(rawProfile);
         exifIO->loadFrom(store, &buffer);
     } else {
         dbgFile << "Decoding failed";
     }
 }
 }
 
 extern "C" {
 static void kis_png_warning(png_structp /*png_ptr*/, png_const_charp message)
 {
     qWarning("libpng warning: %s", message);
 }
 
 }
 
 
 
 
 KisPNGConverter::KisPNGConverter(KisDocument *doc, bool batchMode)
 {
     //     Q_ASSERT(doc);
     //     Q_ASSERT(adapter);
 
     m_doc = doc;
     m_stop = false;
     m_max_row = 0;
     m_image = 0;
     m_batchMode = batchMode;
 }
 
 KisPNGConverter::~KisPNGConverter()
 {
 }
 
 class KisPNGReadStream
 {
 public:
     KisPNGReadStream(quint8* buf,  quint32 depth) : m_posinc(8), m_depth(depth), m_buf(buf) {
     }
     int nextValue() {
         if (m_posinc == 0) {
             m_posinc = 8;
             m_buf++;
         }
         m_posinc -= m_depth;
         return (((*m_buf) >> (m_posinc)) & ((1 << m_depth) - 1));
     }
 private:
     quint32 m_posinc, m_depth;
     quint8* m_buf;
 };
 
 class KisPNGWriteStream
 {
 public:
     KisPNGWriteStream(quint8* buf,  quint32 depth) : m_posinc(8), m_depth(depth), m_buf(buf) {
         *m_buf = 0;
     }
     void setNextValue(int v) {
         if (m_posinc == 0) {
             m_posinc = 8;
             m_buf++;
             *m_buf = 0;
         }
         m_posinc -= m_depth;
         *m_buf = (v << m_posinc) | *m_buf;
     }
 private:
     quint32 m_posinc, m_depth;
     quint8* m_buf;
 };
 
 class KisPNGReaderAbstract
 {
 public:
     KisPNGReaderAbstract(png_structp _png_ptr, int _width, int _height) : png_ptr(_png_ptr), width(_width), height(_height) {}
     virtual ~KisPNGReaderAbstract() {}
     virtual png_bytep readLine() = 0;
 protected:
     png_structp png_ptr;
     int width, height;
 };
 
 class KisPNGReaderLineByLine : public KisPNGReaderAbstract
 {
 public:
     KisPNGReaderLineByLine(png_structp _png_ptr, png_infop info_ptr, int _width, int _height) : KisPNGReaderAbstract(_png_ptr, _width, _height) {
         std::size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
         row_pointer = new png_byte[rowbytes];
     }
     ~KisPNGReaderLineByLine() override {
         delete[] row_pointer;
     }
     png_bytep readLine() override {
         png_read_row(png_ptr, row_pointer, 0);
         return row_pointer;
     }
 private:
     png_bytep row_pointer;
 };
 
 class KisPNGReaderFullImage : public KisPNGReaderAbstract
 {
 public:
     KisPNGReaderFullImage(png_structp _png_ptr, png_infop info_ptr, int _width, int _height) : KisPNGReaderAbstract(_png_ptr, _width, _height), y(0) {
         row_pointers = new png_bytep[height];
         std::size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
         for (int i = 0; i < height; i++) {
             row_pointers[i] = new png_byte[rowbytes];
         }
         png_read_image(png_ptr, row_pointers);
     }
     ~KisPNGReaderFullImage() override {
         for (int i = 0; i < height; i++) {
             delete[] row_pointers[i];
         }
         delete[] row_pointers;
     }
     png_bytep readLine() override {
         return row_pointers[y++];
     }
 private:
     png_bytepp row_pointers;
     int y;
 };
 
 
 static
 void _read_fn(png_structp png_ptr, png_bytep data, png_size_t length)
 {
     QIODevice *in = (QIODevice *)png_get_io_ptr(png_ptr);
 
     while (length) {
         int nr = in->read((char*)data, length);
         if (nr <= 0) {
             png_error(png_ptr, "Read Error");
             return;
         }
         length -= nr;
     }
 }
 
 static
 void _write_fn(png_structp png_ptr, png_bytep data, png_size_t length)
 {
     QIODevice* out = (QIODevice*)png_get_io_ptr(png_ptr);
 
     uint nr = out->write((char*)data, length);
     if (nr != length) {
         png_error(png_ptr, "Write Error");
         return;
     }
 }
 
 static
 void _flush_fn(png_structp png_ptr)
 {
     Q_UNUSED(png_ptr);
 }
 
 KisImportExportErrorCode KisPNGConverter::buildImage(QIODevice* iod)
 {
     dbgFile << "Start decoding PNG File";
 
     png_byte signature[8];
     iod->peek((char*)signature, 8);
 
 #if PNG_LIBPNG_VER < 10400
     if (!png_check_sig(signature, 8)) {
 #else
     if (png_sig_cmp(signature, 0, 8) != 0) {
 #endif
         iod->close();
         return (ImportExportCodes::FileFormatIncorrect);
     }
 
     // Initialize the internal structures
     png_structp png_ptr =  png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
 
     if (!png_ptr) {
         iod->close();
     }
 
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
       /* Remove the user limits, if any */
       png_set_user_limits(png_ptr, 0x7fffffff, 0x7fffffff);
       png_set_chunk_cache_max(png_ptr, 0);
       png_set_chunk_malloc_max(png_ptr, 0);
 #endif
 
     png_set_error_fn(png_ptr, nullptr, nullptr, kis_png_warning);
     #ifdef PNG_BENIGN_ERRORS_SUPPORTED
         png_set_benign_errors(png_ptr, 1);
     #endif
 
     png_infop info_ptr = png_create_info_struct(png_ptr);
     if (!info_ptr) {
         png_destroy_read_struct(&png_ptr, (png_infopp)0, (png_infopp)0);
         iod->close();
         return (ImportExportCodes::Failure);
     }
 
     png_infop end_info = png_create_info_struct(png_ptr);
     if (!end_info) {
         png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)0);
         iod->close();
         return (ImportExportCodes::Failure);
     }
 
     // Catch errors
     if (setjmp(png_jmpbuf(png_ptr))) {
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
         iod->close();
         return (ImportExportCodes::Failure);
     }
 
     // Initialize the special
     png_set_read_fn(png_ptr, iod, _read_fn);
 
 #if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && defined(PNG_SET_OPTION_SUPPORTED)
     png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON);
 #endif
 
     // read all PNG info up to image data
     png_read_info(png_ptr, info_ptr);
 
 
     if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_GRAY && png_get_bit_depth(png_ptr, info_ptr) < 8) {
         png_set_expand(png_ptr);
     }
 
     if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_PALETTE && png_get_bit_depth(png_ptr, info_ptr) < 8) {
         png_set_packing(png_ptr);
     }
 
 
     if (png_get_color_type(png_ptr, info_ptr) != PNG_COLOR_TYPE_PALETTE &&
             (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))) {
         png_set_expand(png_ptr);
     }
     png_read_update_info(png_ptr, info_ptr);
 
     // Read information about the png
     png_uint_32 width, height;
     int color_nb_bits, color_type, interlace_type;
     png_get_IHDR(png_ptr, info_ptr, &width, &height, &color_nb_bits, &color_type, &interlace_type, 0, 0);
     dbgFile << "width = " << width << " height = " << height << " color_nb_bits = " << color_nb_bits << " color_type = " << color_type << " interlace_type = " << interlace_type << endl;
     // swap byteorder on little endian machines.
 #ifndef WORDS_BIGENDIAN
     if (color_nb_bits > 8)
         png_set_swap(png_ptr);
 #endif
 
     // Determine the colorspace
     QPair<QString, QString> csName = getColorSpaceForColorType(color_type, color_nb_bits);
     if (csName.first.isEmpty()) {
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
         iod->close();
         return ImportExportCodes::FormatColorSpaceUnsupported;
     }
     bool hasalpha = (color_type == PNG_COLOR_TYPE_RGB_ALPHA || color_type == PNG_COLOR_TYPE_GRAY_ALPHA);
 
     // Read image profile
     png_charp profile_name;
 #if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 5
     png_bytep profile_data;
 #else
     png_charp profile_data;
 #endif
     int compression_type;
     png_uint_32 proflen;
 
     // Get the various optional chunks
 
     // https://www.w3.org/TR/PNG/#11cHRM
 #if defined(PNG_cHRM_SUPPORTED)
     double whitePointX, whitePointY;
     double redX, redY;
     double greenX, greenY;
     double blueX, blueY;
     png_get_cHRM(png_ptr,info_ptr, &whitePointX, &whitePointY, &redX, &redY, &greenX, &greenY, &blueX, &blueY);
     dbgFile << "cHRM:" << whitePointX << whitePointY << redX << redY << greenX << greenY << blueX << blueY;
 #endif
 
     // https://www.w3.org/TR/PNG/#11gAMA
 #if defined(PNG_GAMMA_SUPPORTED)
     double gamma;
     png_get_gAMA(png_ptr, info_ptr, &gamma);
     dbgFile << "gAMA" << gamma;
 #endif
 
     // https://www.w3.org/TR/PNG/#11sRGB
 #if defined(PNG_sRGB_SUPPORTED)
     int sRGBIntent;
     png_get_sRGB(png_ptr, info_ptr, &sRGBIntent);
     dbgFile << "sRGB" << sRGBIntent;
 #endif
 
     bool fromBlender = false;
 
     png_text* text_ptr;
     int num_comments;
     png_get_text(png_ptr, info_ptr, &text_ptr, &num_comments);
 
     for (int i = 0; i < num_comments; i++) {
         QString key = QString(text_ptr[i].key).toLower();
         if (key == "file") {
             QString relatedFile = text_ptr[i].text;
             if (relatedFile.contains(".blend", Qt::CaseInsensitive)){
                 fromBlender=true;
             }
         }
     }
 
     bool loadedImageIsHDR = false;
     const KoColorProfile* profile = 0;
     if (png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &profile_data, &proflen)) {
         QByteArray profile_rawdata;
         // XXX: Hardcoded for icc type -- is that correct for us?
         profile_rawdata.resize(proflen);
         memcpy(profile_rawdata.data(), profile_data, proflen);
         profile = KoColorSpaceRegistry::instance()->createColorProfile(csName.first, csName.second, profile_rawdata);
         Q_CHECK_PTR(profile);
         if (profile) {
             //                 dbgFile << "profile name: " << profile->productName() << " profile description: " << profile->productDescription() << " information sur le produit: " << profile->productInfo();
             if (!profile->isSuitableForOutput()) {
                 dbgFile << "the profile is not suitable for output and therefore cannot be used in krita, we need to convert the image to a standard profile"; // TODO: in ko2 popup a selection menu to inform the user
             }
         }
 
         loadedImageIsHDR = strcmp(profile_name, "ITUR_2100_PQ_FULL") == 0;
     }
     else {
         dbgFile << "no embedded profile, will use the default profile";
         if (color_nb_bits == 16 && !fromBlender && !qAppName().toLower().contains("test") && !m_batchMode) {
             KisConfig cfg(true);
             quint32 behaviour = cfg.pasteBehaviour();
             if (behaviour == KisClipboard::PASTE_ASK) {
                 KisDlgPngImport dlg(m_path, csName.first, csName.second);
                 KisCursorOverrideHijacker hijacker;
                 Q_UNUSED(hijacker);
                 dlg.exec();
                 if (!dlg.profile().isEmpty()) {
                     profile = KoColorSpaceRegistry::instance()->profileByName(dlg.profile());
                 }
             }
         }
         dbgFile << "no embedded profile, will use the default profile";
     }
 
     const QString colorSpaceId =
         KoColorSpaceRegistry::instance()->colorSpaceId(csName.first, csName.second);
 
     // Check that the profile is used by the color space
     if (profile && !KoColorSpaceRegistry::instance()->profileIsCompatible(profile, colorSpaceId)) {
         warnFile << "The profile " << profile->name() << " is not compatible with the color space model " << csName.first << " " << csName.second;
         profile = 0;
     }
 
     // Retrieve a pointer to the colorspace
     KoColorConversionTransformation* transform = 0;
     const KoColorSpace* cs = 0;
 
     if (loadedImageIsHDR &&
         csName.first == RGBAColorModelID.id() &&
         csName.second == Integer16BitsColorDepthID.id()) {
 
         const KoColorSpace *p2020PQCS =
             KoColorSpaceRegistry::instance()->colorSpace(
                 RGBAColorModelID.id(),
                 Integer16BitsColorDepthID.id(),
                 KoColorSpaceRegistry::instance()->p2020PQProfile());
 
         cs = p2020PQCS;
 
     } else if (profile && profile->isSuitableForOutput()) {
         dbgFile << "image has embedded profile: " << profile->name() << "\n";
         cs = KoColorSpaceRegistry::instance()->colorSpace(csName.first, csName.second, profile);
     }
     else {
         if (csName.first == RGBAColorModelID.id()) {
             cs = KoColorSpaceRegistry::instance()->colorSpace(csName.first, csName.second, "sRGB-elle-V2-srgbtrc.icc");
         } else if (csName.first == GrayAColorModelID.id()) {
             cs = KoColorSpaceRegistry::instance()->colorSpace(csName.first, csName.second, "Gray-D50-elle-V2-srgbtrc.icc");
         } else {
             cs = KoColorSpaceRegistry::instance()->colorSpace(csName.first, csName.second, 0);
         }
 
         //TODO: two fixes : one tell the user about the problem and ask for a solution, and two once the kocolorspace include KoColorTransformation, use that instead of hacking a lcms transformation
         // Create the cmsTransform if needed
         if (profile) {
             transform = KoColorSpaceRegistry::instance()->colorSpace(csName.first, csName.second, profile)->createColorConverter(cs, KoColorConversionTransformation::internalRenderingIntent(), KoColorConversionTransformation::internalConversionFlags());
         }
     }
 
     if (cs == 0) {
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
         return ImportExportCodes::FormatColorSpaceUnsupported;
     }
 
     // Creating the KisImageSP
     if (m_image == 0) {
         KisUndoStore *store = m_doc ? m_doc->createUndoStore() : new KisSurrogateUndoStore();
         m_image = new KisImage(store, width, height, cs, "built image");
     }
 
     // Read resolution
     int unit_type;
     png_uint_32 x_resolution, y_resolution;
 
     png_get_pHYs(png_ptr, info_ptr, &x_resolution, &y_resolution, &unit_type);
     if (x_resolution > 0 && y_resolution > 0 && unit_type == PNG_RESOLUTION_METER) {
         m_image->setResolution((double) POINT_TO_CM(x_resolution) / 100.0, (double) POINT_TO_CM(y_resolution) / 100.0); // It is the "invert" macro because we convert from pointer-per-inchs to points
     }
 
     double coeff = quint8_MAX / (double)(pow((double)2, color_nb_bits) - 1);
     KisPaintLayerSP layer = new KisPaintLayer(m_image.data(), m_image -> nextLayerName(), UCHAR_MAX);
 
     // Read comments/texts...
     png_get_text(png_ptr, info_ptr, &text_ptr, &num_comments);
     if (m_doc) {
         KoDocumentInfo * info = m_doc->documentInfo();
         dbgFile << "There are " << num_comments << " comments in the text";
         for (int i = 0; i < num_comments; i++) {
             QString key = QString(text_ptr[i].key).toLower();
             dbgFile << "key: " << text_ptr[i].key
                     << ", containing: " << text_ptr[i].text
                     << ": " << (key == "raw profile type exif " ? "isExif" : "something else");
             if (key == "title") {
                 info->setAboutInfo("title", text_ptr[i].text);
             } else if (key == "description") {
                 info->setAboutInfo("comment", text_ptr[i].text);
             } else if (key == "author") {
                 info->setAuthorInfo("creator", text_ptr[i].text);
             } else if (key.contains("raw profile type exif")) {
                 decode_meta_data(text_ptr + i, layer->metaData(), "exif", 6);
             } else if (key.contains("raw profile type iptc")) {
                 decode_meta_data(text_ptr + i, layer->metaData(), "iptc", 14);
             } else if (key.contains("raw profile type xmp")) {
                 decode_meta_data(text_ptr + i, layer->metaData(), "xmp", 0);
             } else if (key == "version") {
                 m_image->addAnnotation(new KisAnnotation("kpp_version", "version", QByteArray(text_ptr[i].text)));
             } else if (key == "preset") {
                 m_image->addAnnotation(new KisAnnotation("kpp_preset", "preset", QByteArray(text_ptr[i].text)));
             }
         }
     }
     // Read image data
     QScopedPointer<KisPNGReaderAbstract> reader;
     try {
         if (interlace_type == PNG_INTERLACE_ADAM7) {
             reader.reset(new KisPNGReaderFullImage(png_ptr, info_ptr, width, height));
         } else {
             reader.reset(new KisPNGReaderLineByLine(png_ptr, info_ptr, width, height));
         }
     } catch (const std::bad_alloc& e) {
         // new png_byte[] may raise such an exception if the image
         // is invalid / to large.
         dbgFile << "bad alloc: " << e.what();
         // Free only the already allocated png_byte instances.
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
         return (ImportExportCodes::Failure);
     }
 
     // Read the palette if the file is indexed
     png_colorp palette ;
     int num_palette;
     if (color_type == PNG_COLOR_TYPE_PALETTE) {
         png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette);
     }
 
     // Read the transparency palette
     quint8 palette_alpha[256];
     memset(palette_alpha, 255, 256);
     if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
         if (color_type == PNG_COLOR_TYPE_PALETTE) {
             png_bytep alpha_ptr;
             int num_alpha;
             png_get_tRNS(png_ptr, info_ptr, &alpha_ptr, &num_alpha, 0);
             for (int i = 0; i < num_alpha; ++i) {
                 palette_alpha[i] = alpha_ptr[i];
             }
         }
     }
 
     for (png_uint_32 y = 0; y < height; y++) {
         KisHLineIteratorSP it = layer -> paintDevice() -> createHLineIteratorNG(0, y, width);
 
         png_bytep row_pointer = reader->readLine();
 
         switch (color_type) {
         case PNG_COLOR_TYPE_GRAY:
         case PNG_COLOR_TYPE_GRAY_ALPHA:
             if (color_nb_bits == 16) {
                 quint16 *src = reinterpret_cast<quint16 *>(row_pointer);
                 do {
                     quint16 *d = reinterpret_cast<quint16 *>(it->rawData());
                     d[0] = *(src++);
                     if (hasalpha) {
                         d[1] = *(src++);
                     } else {
                         d[1] = quint16_MAX;
                     }
                     if (transform) transform->transformInPlace(reinterpret_cast<quint8*>(d), reinterpret_cast<quint8*>(d), 1);
                 } while (it->nextPixel());
             } else  {
                 KisPNGReadStream stream(row_pointer, color_nb_bits);
                 do {
                     quint8 *d = it->rawData();
                     d[0] = (quint8)(stream.nextValue() * coeff);
                     if (hasalpha) {
                         d[1] = (quint8)(stream.nextValue() * coeff);
                     } else {
                         d[1] = UCHAR_MAX;
                     }
                     if (transform) transform->transformInPlace(d, d, 1);
                 } while (it->nextPixel());
             }
             // FIXME:should be able to read 1 and 4 bits depth and scale them to 8 bits"
             break;
         case PNG_COLOR_TYPE_RGB:
         case PNG_COLOR_TYPE_RGB_ALPHA:
             if (color_nb_bits == 16) {
                 quint16 *src = reinterpret_cast<quint16 *>(row_pointer);
                 do {
                     quint16 *d = reinterpret_cast<quint16 *>(it->rawData());
                     d[2] = *(src++);
                     d[1] = *(src++);
                     d[0] = *(src++);
                     if (hasalpha) d[3] = *(src++);
                     else d[3] = quint16_MAX;
                     if (transform) transform->transformInPlace(reinterpret_cast<quint8 *>(d), reinterpret_cast<quint8*>(d), 1);
                 } while (it->nextPixel());
             } else {
                 KisPNGReadStream stream(row_pointer, color_nb_bits);
                 do {
                     quint8 *d = it->rawData();
                     d[2] = (quint8)(stream.nextValue() * coeff);
                     d[1] = (quint8)(stream.nextValue() * coeff);
                     d[0] = (quint8)(stream.nextValue() * coeff);
                     if (hasalpha) d[3] = (quint8)(stream.nextValue() * coeff);
                     else d[3] = UCHAR_MAX;
                     if (transform) transform->transformInPlace(d, d, 1);
                 } while (it->nextPixel());
             }
             break;
         case PNG_COLOR_TYPE_PALETTE: {
             KisPNGReadStream stream(row_pointer, color_nb_bits);
             do {
                 quint8 *d = it->rawData();
                 quint8 index = stream.nextValue();
                 quint8 alpha = palette_alpha[ index ];
                 if (alpha == 0) {
                     memset(d, 0, 4);
                 } else {
                     png_color c = palette[ index ];
                     d[2] = c.red;
                     d[1] = c.green;
                     d[0] = c.blue;
                     d[3] = alpha;
                 }
             } while (it->nextPixel());
         }
             break;
         default:
             return ImportExportCodes::FormatFeaturesUnsupported;
         }
     }
     m_image->addNode(layer.data(), m_image->rootLayer().data());
 
     png_read_end(png_ptr, end_info);
     iod->close();
 
     // Freeing memory
     png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
     return ImportExportCodes::OK;
 
 }
 
 KisImportExportErrorCode KisPNGConverter::buildImage(const QString &filename)
 {
     m_path = filename;
 
     QFile fp(filename);
     if (fp.exists()) {
         if (!fp.open(QIODevice::ReadOnly)) {
             dbgFile << "Failed to open PNG File";
             return (ImportExportCodes::FileFormatIncorrect);
         }
 
         return buildImage(&fp);
     }
     return (ImportExportCodes::FileNotExist);
 
 }
 
 
 KisImageSP KisPNGConverter::image()
 {
     return m_image;
 }
 
 bool KisPNGConverter::saveDeviceToStore(const QString &filename, const QRect &imageRect, const qreal xRes, const qreal yRes, KisPaintDeviceSP dev, KoStore *store, KisMetaData::Store* metaData)
 {
     if (store->open(filename)) {
         KoStoreDevice io(store);
         if (!io.open(QIODevice::WriteOnly)) {
             dbgFile << "Could not open for writing:" << filename;
             return false;
         }
         KisPNGConverter pngconv(0);
         vKisAnnotationSP_it annotIt = 0;
         KisMetaData::Store* metaDataStore = 0;
         if (metaData) {
             metaDataStore = new KisMetaData::Store(*metaData);
         }
         KisPNGOptions options;
         options.compression = 3;
         options.interlace = false;
         options.tryToSaveAsIndexed = false;
         options.alpha = true;
         options.saveSRGBProfile = false;
         options.downsample = false;
 
         if (dev->colorSpace()->id() != "RGBA") {
             dev = new KisPaintDevice(*dev.data());
             dev->convertTo(KoColorSpaceRegistry::instance()->rgb8());
         }
 
         KisImportExportErrorCode success = pngconv.buildFile(&io, imageRect, xRes, yRes, dev, annotIt, annotIt, options, metaDataStore);
         if (!success.isOk()) {
             dbgFile << "Saving PNG failed:" << filename;
             delete metaDataStore;
             return false;
         }
         delete metaDataStore;
         io.close();
         if (!store->close()) {
             return false;
         }
     } else {
         dbgFile << "Opening of data file failed :" << filename;
         return false;
     }
     return true;
 
 }
 
 
 KisImportExportErrorCode KisPNGConverter::buildFile(const QString &filename, const QRect &imageRect, const qreal xRes, const qreal yRes, KisPaintDeviceSP device, vKisAnnotationSP_it annotationsStart, vKisAnnotationSP_it annotationsEnd, KisPNGOptions options, KisMetaData::Store* metaData)
 {
     dbgFile << "Start writing PNG File " << filename;
     // Open a QIODevice for writing
     QFile fp (filename);
     if (!fp.open(QIODevice::WriteOnly)) {
         dbgFile << "Failed to open PNG File for writing";
         return (KisImportExportErrorCannotWrite(fp.error()));
     }
 
     KisImportExportErrorCode result = buildFile(&fp, imageRect, xRes, yRes, device, annotationsStart, annotationsEnd, options, metaData);
 
     return result;
 }
 
 KisImportExportErrorCode KisPNGConverter::buildFile(QIODevice* iodevice, const QRect &imageRect, const qreal xRes, const qreal yRes, KisPaintDeviceSP device, vKisAnnotationSP_it annotationsStart, vKisAnnotationSP_it annotationsEnd, KisPNGOptions options, KisMetaData::Store* metaData)
 {
     KIS_SAFE_ASSERT_RECOVER_RETURN_VALUE(device, ImportExportCodes::InternalError);
 
     if (!options.alpha) {
         KisPaintDeviceSP tmp = new KisPaintDevice(device->colorSpace());
         KoColor c(options.transparencyFillColor, device->colorSpace());
         tmp->fill(imageRect, c);
         KisPainter gc(tmp);
         gc.bitBlt(imageRect.topLeft(), device, imageRect);
         gc.end();
         device = tmp;
     }
 
     if (device->colorSpace()->colorDepthId() == Float16BitsColorDepthID
             || device->colorSpace()->colorDepthId() == Float32BitsColorDepthID
             || device->colorSpace()->colorDepthId() == Float64BitsColorDepthID
             || options.saveAsHDR
             || (device->colorSpace()->colorDepthId() != Integer8BitsColorDepthID && options.downsample)) {
 
         const KoColorSpace *dstCS =
             KoColorSpaceRegistry::instance()->colorSpace(
                 device->colorSpace()->colorModelId().id(),
                 options.downsample ? Integer8BitsColorDepthID.id() : Integer16BitsColorDepthID.id(),
                 device->colorSpace()->profile());
 
         if (options.saveAsHDR) {
             dstCS =
                 KoColorSpaceRegistry::instance()->colorSpace(
                         RGBAColorModelID.id(),
                         Integer16BitsColorDepthID.id(),
                         KoColorSpaceRegistry::instance()->p2020PQProfile());
         }
 
         KisPaintDeviceSP tmp = new KisPaintDevice(device->colorSpace());
         tmp->makeCloneFromRough(device, imageRect);
         tmp->convertTo(dstCS);
 
         device = tmp;
     }
 
     KIS_SAFE_ASSERT_RECOVER(!options.saveAsHDR || !options.forceSRGB) {
         options.forceSRGB = false;
     }
 
     KIS_SAFE_ASSERT_RECOVER(!options.saveAsHDR || !options.tryToSaveAsIndexed) {
         options.tryToSaveAsIndexed = false;
     }
 
     QStringList colormodels = QStringList() << RGBAColorModelID.id() << GrayAColorModelID.id();
     if (options.forceSRGB || !colormodels.contains(device->colorSpace()->colorModelId().id())) {
         const KoColorSpace* cs = KoColorSpaceRegistry::instance()->colorSpace(RGBAColorModelID.id(), options.downsample ? Integer8BitsColorDepthID.id() : device->colorSpace()->colorDepthId().id(), "sRGB built-in - (lcms internal)");
         device = new KisPaintDevice(*device);
         device->convertTo(cs);
     }
 
     // Initialize structures
     png_structp png_ptr =  png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
     if (!png_ptr) {
         return (ImportExportCodes::Failure);
     }
 
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
       /* Remove the user limits, if any */
       png_set_user_limits(png_ptr, 0x7fffffff, 0x7fffffff);
       png_set_chunk_cache_max(png_ptr, 0);
       png_set_chunk_malloc_max(png_ptr, 0);
 #endif
 
     png_set_error_fn(png_ptr, nullptr, nullptr, kis_png_warning);
     #ifdef PNG_BENIGN_ERRORS_SUPPORTED
         png_set_benign_errors(png_ptr, 1);
     #endif
 
 #if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && defined(PNG_SET_OPTION_SUPPORTED)
     png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON);
 #endif
 
 
 #ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
     png_set_check_for_invalid_index(png_ptr, 0);
 #endif
 
     png_infop info_ptr = png_create_info_struct(png_ptr);
     if (!info_ptr) {
         png_destroy_write_struct(&png_ptr, (png_infopp)0);
         return (ImportExportCodes::Failure);
     }
 
     // If an error occurs during writing, libpng will jump here
     if (setjmp(png_jmpbuf(png_ptr))) {
         png_destroy_write_struct(&png_ptr, &info_ptr);
         return (ImportExportCodes::Failure);
     }
     // Initialize the writing
     //     png_init_io(png_ptr, fp);
     // Setup the progress function
     // XXX: Implement progress updating -- png_set_write_status_fn(png_ptr, progress);"
     //     setProgressTotalSteps(100/*height*/);
 
     /* set the zlib compression level */
     png_set_compression_level(png_ptr, options.compression);
 
     png_set_write_fn(png_ptr, (void*)iodevice, _write_fn, _flush_fn);
 
     /* set other zlib parameters */
     png_set_compression_mem_level(png_ptr, 8);
     png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
     png_set_compression_window_bits(png_ptr, 15);
     png_set_compression_method(png_ptr, 8);
     png_set_compression_buffer_size(png_ptr, 8192);
 
     int color_nb_bits = 8 * device->pixelSize() / device->channelCount();
     int color_type = getColorTypeforColorSpace(device->colorSpace(), options.alpha);
 
     Q_ASSERT(color_type > -1);
 
     // Try to compute a table of color if the colorspace is RGB8f
     QScopedArrayPointer<png_color> palette;
     int num_palette = 0;
     if (!options.alpha && options.tryToSaveAsIndexed && KoID(device->colorSpace()->id()) == KoID("RGBA")) { // png doesn't handle indexed images and alpha, and only have indexed for RGB8
         palette.reset(new png_color[255]);
 
         KisSequentialIterator it(device, imageRect);
 
         bool toomuchcolor = false;
         while (it.nextPixel()) {
             const quint8* c = it.oldRawData();
             bool findit = false;
             for (int i = 0; i < num_palette; i++) {
                 if (palette[i].red == c[2] &&
                         palette[i].green == c[1] &&
                         palette[i].blue == c[0]) {
                     findit = true;
                     break;
                 }
             }
             if (!findit) {
                 if (num_palette == 255) {
                     toomuchcolor = true;
                     break;
                 }
                 palette[num_palette].red = c[2];
                 palette[num_palette].green = c[1];
                 palette[num_palette].blue = c[0];
                 num_palette++;
             }
         }
 
         if (!toomuchcolor) {
             dbgFile << "Found a palette of " << num_palette << " colors";
             color_type = PNG_COLOR_TYPE_PALETTE;
             if (num_palette <= 2) {
                 color_nb_bits = 1;
             } else if (num_palette <= 4) {
                 color_nb_bits = 2;
             } else if (num_palette <= 16) {
                 color_nb_bits = 4;
             } else {
                 color_nb_bits = 8;
             }
         } else {
             palette.reset();
         }
     }
 
     int interlacetype = options.interlace ? PNG_INTERLACE_ADAM7 : PNG_INTERLACE_NONE;
 
     KIS_SAFE_ASSERT_RECOVER_RETURN_VALUE(color_type >= 0, ImportExportCodes::Failure);
 
     png_set_IHDR(png_ptr, info_ptr,
                  imageRect.width(),
                  imageRect.height(),
                  color_nb_bits,
                  color_type, interlacetype,
                  PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 
     // set sRGB only if the profile is sRGB  -- http://www.w3.org/TR/PNG/#11sRGB says sRGB and iCCP should not both be present
 
     const bool sRGB = *device->colorSpace()->profile() == *KoColorSpaceRegistry::instance()->p709SRGBProfile();
     /*
      * This automatically writes the correct gamma and chroma chunks along with the sRGB chunk, but firefox's
      * color management is bugged, so once you give it any incentive to start color managing an sRGB image it
      * will turn, for example, a nice desaturated rusty red into bright poppy red. So this is disabled for now.
      */
     /*if (!options.saveSRGBProfile && sRGB) {
         png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
     }*/
 
 
     /** TODO: Firefox still opens the image incorrectly if there is gAMA+cHRM tags
      * present. According to the standard it should use iCCP tag with higher priority,
      * but it doesn't:
      *
      * "When the iCCP chunk is present, PNG decoders that recognize it and are capable
      *  of color management [ICC] shall ignore the gAMA and cHRM chunks and use
      *  the iCCP chunk instead and interpret it according to [ICC-1] and [ICC-1A]"
      */
 
 #if 0
     if (options.saveAsHDR) {
         // https://www.w3.org/TR/PNG/#11gAMA
 #if defined(PNG_GAMMA_SUPPORTED)
         // the values are set in accordance of HDR-PNG standard:
         // https://www.w3.org/TR/png-hdr-pq/
 
         png_set_gAMA_fixed(png_ptr, info_ptr, 15000);
         dbgFile << "gAMA" << "(Rec 2100)";
 #endif
 
 #if defined PNG_cHRM_SUPPORTED
         png_set_cHRM_fixed(png_ptr, info_ptr,
                            31270, 32900, // white point
                            70800, 29200, // red
                            17000, 79700, // green
                            13100, 4600 // blue
                            );
         dbgFile << "cHRM" << "(Rec 2100)";
 #endif
     }
 #endif
 
 
     // we should ensure we don't access non-existing palette object
     KIS_SAFE_ASSERT_RECOVER_RETURN_VALUE(palette || color_type != PNG_COLOR_TYPE_PALETTE, ImportExportCodes::Failure);
 
     // set the palette
     if (color_type == PNG_COLOR_TYPE_PALETTE) {
         png_set_PLTE(png_ptr, info_ptr, palette.data(), num_palette);
     }
     // Save annotation
     vKisAnnotationSP_it it = annotationsStart;
     while (it != annotationsEnd) {
         if (!(*it) || (*it)->type().isEmpty()) {
             dbgFile << "Warning: empty annotation";
             it++;
             continue;
         }
 
         dbgFile << "Trying to store annotation of type " << (*it) -> type() << " of size " << (*it) -> annotation() . size();
 
         if ((*it) -> type().startsWith(QString("krita_attribute:"))) { //
             // Attribute
             // XXX: it should be possible to save krita_attributes in the \"CHUNKs\""
             dbgFile << "cannot save this annotation : " << (*it) -> type();
         } else if ((*it)->type() == "kpp_version" || (*it)->type() == "kpp_preset" ) {
             dbgFile << "Saving preset information " << (*it)->description();
             png_textp      text = (png_textp) png_malloc(png_ptr, (png_uint_32) sizeof(png_text));
 
             QByteArray keyData = (*it)->description().toLatin1();
             text[0].key = keyData.data();
             text[0].text = (char*)(*it)->annotation().data();
             text[0].text_length = (*it)->annotation().size();
             text[0].compression = -1;
 
             png_set_text(png_ptr, info_ptr, text, 1);
             png_free(png_ptr, text);
         }
         it++;
     }
 
     // Save the color profile
     const KoColorProfile* colorProfile = device->colorSpace()->profile();
     QByteArray colorProfileData = colorProfile->rawData();
     if (!sRGB || options.saveSRGBProfile) {
 
 #if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 5
         const char *typeString = !options.saveAsHDR ? "icc" : "ITUR_2100_PQ_FULL";
         png_set_iCCP(png_ptr, info_ptr, (png_const_charp)typeString, PNG_COMPRESSION_TYPE_BASE, (png_const_bytep)colorProfileData.constData(), colorProfileData . size());
 #else
         // older version of libpng has a problem with constness on the parameters
         char typeStringICC[] = "icc";
         char typeStringHDR[] = "ITUR_2100_PQ_FULL";
         char *typeString = !options.saveAsHDR ? typeStringICC : typeStringHDR;
         png_set_iCCP(png_ptr, info_ptr, typeString, PNG_COMPRESSION_TYPE_BASE, colorProfileData.data(), colorProfileData . size());
 #endif
     }
 
     // save comments from the document information
     // warning: according to the official png spec, the keys need to be capitalized!
     if (m_doc) {
         png_text texts[4];
         int nbtexts = 0;
         KoDocumentInfo * info = m_doc->documentInfo();
         QString title = info->aboutInfo("title");
         if (!title.isEmpty() && options.storeMetaData) {
             fillText(texts + nbtexts, "Title", title);
             nbtexts++;
         }
         QString abstract = info->aboutInfo("subject");
         if (abstract.isEmpty()) {
             abstract = info->aboutInfo("abstract");
         }
         if (!abstract.isEmpty() && options.storeMetaData) {
             QString keywords = info->aboutInfo("keyword");
             if (!keywords.isEmpty()) {
                 abstract = abstract + " keywords: " + keywords;
             }
             fillText(texts + nbtexts, "Description", abstract);
             nbtexts++;
         }
 
         QString license = info->aboutInfo("license");
         if (!license.isEmpty() && options.storeMetaData) {
             fillText(texts + nbtexts, "Copyright", license);
             nbtexts++;
         }
 
         QString author = info->authorInfo("creator");
         if (!author.isEmpty() && options.storeAuthor) {
             if (!info->authorContactInfo().isEmpty()) {
                 QString contact = info->authorContactInfo().at(0);
                 if (!contact.isEmpty()) {
                     author = author+"("+contact+")";
                 }
             }
             fillText(texts + nbtexts, "Author", author);
             nbtexts++;
         }
 
         png_set_text(png_ptr, info_ptr, texts, nbtexts);
     }
 
     // Save metadata following imagemagick way
 
     // Save exif
     if (metaData && !metaData->empty()) {
         if (options.exif) {
             dbgFile << "Trying to save exif information";
 
             KisMetaData::IOBackend *exifIO = KisMetadataBackendRegistry::instance()->value("exif");
             Q_ASSERT(exifIO);
 
             QBuffer buffer;
             exifIO->saveTo(metaData, &buffer, KisMetaData::IOBackend::JpegHeader);
             writeRawProfile(png_ptr, info_ptr, "exif", buffer.data());
         }
         // Save IPTC
         if (options.iptc) {
             dbgFile << "Trying to save iptc information";
             KisMetaData::IOBackend *iptcIO = KisMetadataBackendRegistry::instance()->value("iptc");
             Q_ASSERT(iptcIO);
 
             QBuffer buffer;
             iptcIO->saveTo(metaData, &buffer, KisMetaData::IOBackend::JpegHeader);
 
             dbgFile << "IPTC information size is" << buffer.data().size();
             writeRawProfile(png_ptr, info_ptr, "iptc", buffer.data());
         }
         // Save XMP
         if (options.xmp) {
             dbgFile << "Trying to save XMP information";
             KisMetaData::IOBackend *xmpIO = KisMetadataBackendRegistry::instance()->value("xmp");
             Q_ASSERT(xmpIO);
 
             QBuffer buffer;
             xmpIO->saveTo(metaData, &buffer, KisMetaData::IOBackend::NoHeader);
 
             dbgFile << "XMP information size is" << buffer.data().size();
             writeRawProfile(png_ptr, info_ptr, "xmp", buffer.data());
         }
     }
 #if 0 // Unimplemented?
     // Save resolution
     int unit_type;
     png_uint_32 x_resolution, y_resolution;
 #endif
     png_set_pHYs(png_ptr, info_ptr, CM_TO_POINT(xRes) * 100.0, CM_TO_POINT(yRes) * 100.0, PNG_RESOLUTION_METER); // It is the "invert" macro because we convert from pointer-per-inchs to points
 
     // Save the information to the file
     png_write_info(png_ptr, info_ptr);
     png_write_flush(png_ptr);
 
     // swap byteorder on little endian machines.
 #ifndef WORDS_BIGENDIAN
     if (color_nb_bits > 8)
         png_set_swap(png_ptr);
 #endif
 
     // Write the PNG
     //     png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, 0);
 
     struct RowPointersStruct {
         RowPointersStruct(const QSize &size, int pixelSize)
             : numRows(size.height())
         {
             rows = new png_byte*[numRows];
 
             for (int i = 0; i < numRows; i++) {
                 rows[i] = new png_byte[size.width() * pixelSize];
             }
         }
 
         ~RowPointersStruct() {
             for (int i = 0; i < numRows; i++) {
                 delete[] rows[i];
             }
             delete[] rows;
         }
 
         const int numRows = 0;
         png_byte** rows = 0;
     };
 
 
     // Fill the data structure
     RowPointersStruct rowPointers(imageRect.size(), device->pixelSize());
 
     int row = 0;
     for (int y = imageRect.y(); y < imageRect.y() + imageRect.height(); y++, row++) {
         KisHLineConstIteratorSP it = device->createHLineConstIteratorNG(imageRect.x(), y, imageRect.width());
 
         switch (color_type) {
         case PNG_COLOR_TYPE_GRAY:
         case PNG_COLOR_TYPE_GRAY_ALPHA:
             if (color_nb_bits == 16) {
                 quint16 *dst = reinterpret_cast<quint16 *>(rowPointers.rows[row]);
                 do {
                     const quint16 *d = reinterpret_cast<const quint16 *>(it->oldRawData());
                     *(dst++) = d[0];
                     if (options.alpha) *(dst++) = d[1];
                 } while (it->nextPixel());
             } else {
                 quint8 *dst = rowPointers.rows[row];
                 do {
                     const quint8 *d = it->oldRawData();
                     *(dst++) = d[0];
                     if (options.alpha) *(dst++) = d[1];
                 } while (it->nextPixel());
             }
             break;
         case PNG_COLOR_TYPE_RGB:
         case PNG_COLOR_TYPE_RGB_ALPHA:
             if (color_nb_bits == 16) {
                 quint16 *dst = reinterpret_cast<quint16 *>(rowPointers.rows[row]);
                 do {
                     const quint16 *d = reinterpret_cast<const quint16 *>(it->oldRawData());
                     *(dst++) = d[2];
                     *(dst++) = d[1];
                     *(dst++) = d[0];
                     if (options.alpha) *(dst++) = d[3];
                 } while (it->nextPixel());
             } else {
                 quint8 *dst = rowPointers.rows[row];
                 do {
                     const quint8 *d = it->oldRawData();
                     *(dst++) = d[2];
                     *(dst++) = d[1];
                     *(dst++) = d[0];
                     if (options.alpha) *(dst++) = d[3];
                 } while (it->nextPixel());
             }
             break;
         case PNG_COLOR_TYPE_PALETTE: {
             quint8 *dst = rowPointers.rows[row];
             KisPNGWriteStream writestream(dst, color_nb_bits);
             do {
                 const quint8 *d = it->oldRawData();
                 int i;
                 for (i = 0; i < num_palette; i++) {
                     if (palette[i].red == d[2] &&
                             palette[i].green == d[1] &&
                             palette[i].blue == d[0]) {
                         break;
                     }
                 }
                 writestream.setNextValue(i);
             } while (it->nextPixel());
         }
             break;
         default:
             return ImportExportCodes::FormatColorSpaceUnsupported;
         }
     }
 
     png_write_image(png_ptr, rowPointers.rows);
 
     // Writing is over
     png_write_end(png_ptr, info_ptr);
 
     // Free memory
     png_destroy_write_struct(&png_ptr, &info_ptr);
     return ImportExportCodes::OK;
 }
 
 
 void KisPNGConverter::cancel()
 {
     m_stop = true;
 }
 
 void KisPNGConverter::progress(png_structp png_ptr, png_uint_32 row_number, int pass)
 {
     if (png_ptr == 0 || row_number > PNG_MAX_UINT || pass > 7) return;
     //     setProgress(row_number);
 }
 
 bool KisPNGConverter::isColorSpaceSupported(const KoColorSpace *cs)
 {
     return colorSpaceIdSupported(cs->id());
 }