File indexing completed on 2025-01-19 03:51:02

 /* ============================================================
  *
  * This file is a part of digiKam project
  * https://www.digikam.org
  *
  * Date        : 2005-11-01
  * Description : a PNG image loader for DImg framework - load operations.
  *
  * SPDX-FileCopyrightText: 2005-2024 by Gilles Caulier <caulier dot gilles at gmail dot com>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ============================================================ */
 
 #define PNG_BYTES_TO_CHECK 4
 
 #include "dimgpngloader.h"
 
 // C ANSI includes
 
 extern "C"
 {
 #ifndef Q_CC_MSVC
 #   include <unistd.h>
 #endif
 }
 
 // C++ includes
 
 #include <cstdlib>
 #include <cstdio>
 
 // Qt includes
 
 #include <QFile>
 #include <QByteArray>
 #include <QSysInfo>
 
 // Local includes
 
 #include "metaengine.h"
 #include "digikam_debug.h"
 #include "digikam_config.h"
 #include "digikam_version.h"
 #include "dimgloaderobserver.h"
 
 // libPNG includes
 
 extern "C"
 {
 #include <png.h>
 }
 
 #ifdef Q_OS_WIN
 
 void _ReadProc(struct png_struct_def* png_ptr, png_bytep data, png_size_t size)
 {
     FILE* const file_handle = (FILE*)png_get_io_ptr(png_ptr);
     fread(data, size, 1, file_handle);
 }
 
 #endif
 
 using namespace Digikam;
 
 namespace DigikamPNGDImgPlugin
 {
 
 #if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 5
 
 typedef png_bytep iCCP_data;
 
 #else
 
 typedef png_charp iCCP_data;
 
 #endif
 
 bool DImgPNGLoader::load(const QString& filePath, DImgLoaderObserver* const observer)
 {
     png_uint_32  w32, h32;
     int          width, height;
     int          bit_depth, color_type, interlace_type;
     FILE*        f          = nullptr;
     png_structp  png_ptr    = nullptr;
     png_infop    info_ptr   = nullptr;
 
     // To prevent cppcheck warnings.
     (void)f;
     (void)png_ptr;
     (void)info_ptr;
 
     readMetadata(filePath);
 
     // -------------------------------------------------------------------
     // Open the file
 
     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "Opening file" << filePath;
 
 #ifdef Q_OS_WIN
 
     f = _wfopen((const wchar_t*)filePath.utf16(), L"rb");
 
 #else
 
     f = fopen(filePath.toUtf8().constData(), "rb");
 
 #endif
 
     if (!f)
     {
         qCWarning(DIGIKAM_DIMG_LOG_PNG) << "Cannot open image file.";
         loadingFailed();
         return false;
     }
 
     unsigned char buf[PNG_BYTES_TO_CHECK];
 
     size_t membersRead = fread(buf, 1, PNG_BYTES_TO_CHECK, f);
 
 #if PNG_LIBPNG_VER >= 10400
 
     if ((membersRead != PNG_BYTES_TO_CHECK) || png_sig_cmp(buf, 0, PNG_BYTES_TO_CHECK))
 
 #else
 
     if ((membersRead != PNG_BYTES_TO_CHECK) || !png_check_sig(buf, PNG_BYTES_TO_CHECK))
 
 #endif
     {
         qCWarning(DIGIKAM_DIMG_LOG_PNG) << "Not a PNG image file.";
         fclose(f);
         loadingFailed();
         return false;
     }
 
     rewind(f);
 
     // -------------------------------------------------------------------
     // Initialize the internal structures
 
     png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
 
     if (!png_ptr)
     {
         qCWarning(DIGIKAM_DIMG_LOG_PNG) << "Invalid PNG image file structure.";
         fclose(f);
         loadingFailed();
         return false;
     }
 
     info_ptr = png_create_info_struct(png_ptr);
 
     if (!info_ptr)
     {
         qCWarning(DIGIKAM_DIMG_LOG_PNG) << "Cannot reading PNG image file structure.";
         png_destroy_read_struct(&png_ptr, nullptr, nullptr);
         fclose(f);
         loadingFailed();
         return false;
     }
 
     // -------------------------------------------------------------------
     // PNG error handling. If an error occurs during reading, libpng
     // will jump here
 
     // setjmp-save cleanup
     class Q_DECL_HIDDEN CleanupData
     {
 
     public:
 
         CleanupData()
           : data (nullptr),
             lines(nullptr),
             file (nullptr),
             cmod (0)
         {
         }
 
         ~CleanupData()
         {
             delete [] data;
             freeLines();
 
             if (file)
             {
                 fclose(file);
             }
         }
 
         void setData(uchar* const d)
         {
             data = d;
         }
 
         void setLines(uchar** const l)
         {
             lines = l;
         }
 
         void setFile(FILE* const f)
         {
             file = f;
         }
 
         void setSize(const QSize& s)
         {
             size = s;
         }
 
         void setColorModel(int c)
         {
             cmod = c;
         }
 
         void takeData()
         {
             data = nullptr;
         }
 
         void freeLines()
         {
             if (lines)
             {
                 free(lines);
             }
 
             lines = nullptr;
         }
 
     public:
 
         uchar*  data;
         uchar** lines;
         FILE*   file;
 
         QSize  size;
         int    cmod;
     };
 
     CleanupData* const cleanupData = new CleanupData;
     cleanupData->setFile(f);
 
 #if PNG_LIBPNG_VER >= 10400
 
     if (setjmp(png_jmpbuf(png_ptr)))
 
 #else
 
     if (setjmp(png_ptr->jmpbuf))
 
 #endif
     {
         png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) nullptr);
 
         if (!cleanupData->data ||
             !cleanupData->size.isValid())
         {
             qCWarning(DIGIKAM_DIMG_LOG_PNG) << "Internal libPNG error during reading file. Process aborted!";
             delete cleanupData;
             loadingFailed();
             return false;
         }
 
         // We check only Exif metadata for ICC profile to prevent endless loop
 
         if (m_loadFlags & LoadICCData)
         {
             checkExifWorkingColorSpace();
         }
 
         if (observer)
         {
             observer->progressInfo(1.0F);
         }
 
         imageWidth()  = cleanupData->size.width();
         imageHeight() = cleanupData->size.height();
         imageData()   = cleanupData->data;
         imageSetAttribute(QLatin1String("format"),             QLatin1String("PNG"));
         imageSetAttribute(QLatin1String("originalColorModel"), cleanupData->cmod);
         imageSetAttribute(QLatin1String("originalBitDepth"),   m_sixteenBit ? 16 : 8);
         imageSetAttribute(QLatin1String("originalSize"),       cleanupData->size);
 
         cleanupData->takeData();
         delete cleanupData;
         return true;
     }
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 
     // Change some libpng errors to warnings (e.g. bug 386396).
 
     png_set_benign_errors(png_ptr, true);
 
     png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON);
 
 #endif
 
 #ifdef Q_OS_WIN
 
     png_set_read_fn(png_ptr, f, _ReadProc);
 
 #else
 
     png_init_io(png_ptr, f);
 
 #endif
 
     // -------------------------------------------------------------------
     // Read all PNG info up to image data
 
     png_read_info(png_ptr, info_ptr);
 
     png_get_IHDR(png_ptr,
                  info_ptr,
                  (png_uint_32*)(&w32),
                  (png_uint_32*)(&h32),
                  &bit_depth,
                  &color_type,
                  &interlace_type,
                  nullptr,
                  nullptr);
 
     width  = (int)w32;
     height = (int)h32;
 
     int colorModel = DImg::COLORMODELUNKNOWN;
     m_sixteenBit   = (bit_depth == 16);
 
     switch (color_type)
     {
         case PNG_COLOR_TYPE_RGB:           // RGB
         {
             m_hasAlpha = false;
             colorModel = DImg::RGB;
             break;
         }
 
         case PNG_COLOR_TYPE_RGB_ALPHA:     // RGBA
         {
             m_hasAlpha = true;
             colorModel = DImg::RGB;
             break;
         }
 
         case PNG_COLOR_TYPE_GRAY:          // Grayscale
         {
             m_hasAlpha = false;
             colorModel = DImg::GRAYSCALE;
             break;
         }
 
         case PNG_COLOR_TYPE_GRAY_ALPHA:    // Grayscale + Alpha
         {
             m_hasAlpha = true;
             colorModel = DImg::GRAYSCALE;
             break;
         }
 
         case PNG_COLOR_TYPE_PALETTE:       // Indexed
         {
             m_hasAlpha = false;
             colorModel = DImg::INDEXED;
             break;
         }
     }
 
     cleanupData->setColorModel(colorModel);
     cleanupData->setSize(QSize(width, height));
 
     uchar* data  = nullptr;
 
     if (m_loadFlags & LoadImageData)
     {
         // TODO: Endianness:
         // You may notice that the code for little and big endian
         // below is now identical. This was found to work by PPC users.
         // If this proves right, all the conditional clauses can be removed.
 
         if (bit_depth == 16)
         {
             qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in 16 bits/color/pixel.";
 
             switch (color_type)
             {
                 case PNG_COLOR_TYPE_RGB :           // RGB
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_RGB";
 
                     png_set_add_alpha(png_ptr, 0xFFFF, PNG_FILLER_AFTER);
                     break;
                 }
 
                 case PNG_COLOR_TYPE_RGB_ALPHA :     // RGBA
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_RGB_ALPHA";
                     break;
                 }
 
                 case PNG_COLOR_TYPE_GRAY :          // Grayscale
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_GRAY";
 
                     png_set_gray_to_rgb(png_ptr);
                     png_set_add_alpha(png_ptr, 0xFFFF, PNG_FILLER_AFTER);
 
                     break;
                 }
 
                 case PNG_COLOR_TYPE_GRAY_ALPHA :    // Grayscale + Alpha
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_GRAY_ALPHA";
 
                     png_set_gray_to_rgb(png_ptr);
 
                     break;
                 }
 
                 case PNG_COLOR_TYPE_PALETTE :       // Indexed
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_PALETTE";
 
                     png_set_palette_to_rgb(png_ptr);
                     png_set_add_alpha(png_ptr, 0xFFFF, PNG_FILLER_AFTER);
 
                     break;
                 }
 
                 default:
                 {
                     qCWarning(DIGIKAM_DIMG_LOG_PNG) << "PNG color type unknown.";
 
                     delete cleanupData;
                     loadingFailed();
                     return false;
                 }
             }
         }
         else
         {
             qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in >=8 bits/color/pixel.";
 
             png_set_packing(png_ptr);
 
             switch (color_type)
             {
                 case PNG_COLOR_TYPE_RGB :           // RGB
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_RGB";
 
                     png_set_add_alpha(png_ptr, 0xFF, PNG_FILLER_AFTER);
 
                     break;
                 }
 
                 case PNG_COLOR_TYPE_RGB_ALPHA :     // RGBA
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_RGB_ALPHA";
 
                     break;
                 }
 
                 case PNG_COLOR_TYPE_GRAY :          // Grayscale
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_GRAY";
 
 #if PNG_LIBPNG_VER >= 10400
 
                     png_set_expand_gray_1_2_4_to_8(png_ptr);
 
 #else
 
                     png_set_gray_1_2_4_to_8(png_ptr);
 
 #endif
 
                     png_set_gray_to_rgb(png_ptr);
                     png_set_add_alpha(png_ptr, 0xFF, PNG_FILLER_AFTER);
 
                     break;
                 }
 
                 case PNG_COLOR_TYPE_GRAY_ALPHA :    // Grayscale + alpha
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_GRAY_ALPHA";
 
                     png_set_gray_to_rgb(png_ptr);
                     break;
                 }
 
                 case PNG_COLOR_TYPE_PALETTE :       // Indexed
                 {
                     qCDebug(DIGIKAM_DIMG_LOG_PNG) << "PNG in PNG_COLOR_TYPE_PALETTE";
 
                     png_set_packing(png_ptr);
                     png_set_palette_to_rgb(png_ptr);
                     png_set_add_alpha(png_ptr, 0xFF, PNG_FILLER_AFTER);
 
                     break;
                 }
 
                 default:
                 {
                     qCWarning(DIGIKAM_DIMG_LOG_PNG) << "PNG color type unknown." << color_type;
 
                     delete cleanupData;
                     loadingFailed();
                     return false;
                 }
             }
         }
 
         if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
         {
             png_set_tRNS_to_alpha(png_ptr);
         }
 
         double file_gamma;
 
         if (png_get_gAMA(png_ptr, info_ptr, &file_gamma))
         {
             qCDebug(DIGIKAM_DIMG_LOG_PNG) << "Apply PNG file gamma" << file_gamma;
 
             png_set_gamma(png_ptr, 2.2, file_gamma);
         }
 
         png_set_bgr(png_ptr);
 
         //png_set_swap_alpha(png_ptr);
 
         if (observer)
         {
             observer->progressInfo(0.1F);
         }
 
         // -------------------------------------------------------------------
         // Get image data.
 
         // Call before png_read_update_info and png_start_read_image()
         // for non-interlaced images number_passes will be 1
         int number_passes = png_set_interlace_handling(png_ptr);
 
         png_read_update_info(png_ptr, info_ptr);
 
         if (m_sixteenBit)
         {
             data = new_failureTolerant(width, height, 8); // 16 bits/color/pixel
         }
         else
         {
             data = new_failureTolerant(width, height, 4); // 8 bits/color/pixel
         }
 
         cleanupData->setData(data);
 
         uchar** lines = nullptr;
         (void)lines;    // to prevent cppcheck warnings.
         lines         = (uchar**)malloc(height * sizeof(uchar*));
         cleanupData->setLines(lines);
 
         if (!data || !lines)
         {
             qCDebug(DIGIKAM_DIMG_LOG_PNG) << "Cannot allocate memory to load PNG image data.";
             png_read_end(png_ptr, info_ptr);
             png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) nullptr);
             delete cleanupData;
             loadingFailed();
             return false;
         }
 
         for (int i = 0 ; i < height ; ++i)
         {
             if (m_sixteenBit)
             {
                 lines[i] = data + ((quint64)i * (quint64)width * 8);
             }
             else
             {
                 lines[i] = data + ((quint64)i * (quint64)width * 4);
             }
         }
 
         // The easy way to read the whole image
         // png_read_image(png_ptr, lines);
         // The other way to read images is row by row. Necessary for observer.
         // Now we need to deal with interlacing.
 
         for (int pass = 0 ; pass < number_passes ; ++pass)
         {
             int checkPoint = 0;
 
             for (int y = 0 ; y < height ; ++y)
             {
                 if (observer && y == checkPoint)
                 {
                     checkPoint += granularity(observer, height, 0.7F);
 
                     if (!observer->continueQuery())
                     {
                         png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) nullptr);
                         delete cleanupData;
                         loadingFailed();
                         return false;
                     }
 
                     // use 10% - 80% for progress while reading rows
                     observer->progressInfo(0.1F + (0.7F * (((float)y) / ((float)height))));
                 }
 
                 png_read_rows(png_ptr, lines + y, nullptr, 1);
             }
         }
 
         cleanupData->freeLines();
 
         if (QSysInfo::ByteOrder == QSysInfo::LittleEndian)
         {
             // Swap bytes in 16 bits/color/pixel for DImg
 
             if (m_sixteenBit)
             {
                 uchar ptr[8];   // One pixel to swap
 
                 for (uint p = 0 ; p < (uint)width * height * 8 ; p += 8)
                 {
                     memcpy(&ptr[0], &data[p], 8);   // Current pixel
 
                     data[  p  ] = ptr[1]; // Blue
                     data[p + 1] = ptr[0];
                     data[p + 2] = ptr[3]; // Green
                     data[p + 3] = ptr[2];
                     data[p + 4] = ptr[5]; // Red
                     data[p + 5] = ptr[4];
                     data[p + 6] = ptr[7]; // Alpha
                     data[p + 7] = ptr[6];
                 }
             }
         }
     }
 
     if (observer)
     {
         observer->progressInfo(0.9F);
     }
 
     // -------------------------------------------------------------------
     // Read image ICC profile
 
     if (m_loadFlags & LoadICCData)
     {
         png_charp   profile_name;
         iCCP_data   profile_data = nullptr;
         png_uint_32 profile_size;
         int         compression_type;
 
         png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &profile_data, &profile_size);
 
         if (profile_data != nullptr)
         {
             QByteArray profile_rawdata;
             profile_rawdata.resize(profile_size);
             memcpy(profile_rawdata.data(), profile_data, profile_size);
             imageSetIccProfile(IccProfile(profile_rawdata));
         }
         else
         {
             // If ICC profile is null, check Exif metadata.
 
             checkExifWorkingColorSpace();
         }
     }
 
     // -------------------------------------------------------------------
     // Get embedded text data.
 
     png_text* text_ptr = nullptr;
     int num_comments   = png_get_text(png_ptr, info_ptr, &text_ptr, nullptr);
 
     /*
     Standard Embedded text includes in PNG :
 
     Title            Short (one line) title or caption for image
     Author           Name of image's creator
     Description      Description of image (possibly long)
     Copyright        Copyright notice
     Creation Time    Time of original image creation
     Software         Software used to create the image
     Disclaimer       Legal disclaimer
     Warning          Warning of nature of content
     Source           Device used to create the image
     Comment          Miscellaneous comment; conversion from GIF comment
 
     Extra Raw profiles tag are used by ImageMagick and defines at this Url:
     search.cpan.org/src/EXIFTOOL/Image-ExifTool-5.87/html/TagNames/PNG.html#TextualData
     */
 
     if (m_loadFlags & LoadICCData)
     {
         for (int i = 0 ; i < num_comments ; ++i)
         {
             // Check if we have a Raw profile embedded using ImageMagick technique.
 
             if (memcmp(text_ptr[i].key, "Raw profile type exif", 21) != 0 ||
                 memcmp(text_ptr[i].key, "Raw profile type APP1", 21) != 0 ||
                 memcmp(text_ptr[i].key, "Raw profile type iptc", 21) != 0)
             {
                 imageSetEmbbededText(QLatin1String(text_ptr[i].key), QLatin1String(text_ptr[i].text));
 
                 qCDebug(DIGIKAM_DIMG_LOG_PNG) << "Reading PNG Embedded text: key=" << text_ptr[i].key
                                               << "size=" << QLatin1String(text_ptr[i].text).size();
             }
         }
     }
 
     // -------------------------------------------------------------------
 
     if (m_loadFlags & LoadImageData)
     {
         png_read_end(png_ptr, info_ptr);
     }
 
     png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) nullptr);
     cleanupData->takeData();
     delete cleanupData;
 
     if (observer)
     {
         observer->progressInfo(1.0F);
     }
 
     imageWidth()  = width;
     imageHeight() = height;
     imageData()   = data;
     imageSetAttribute(QLatin1String("format"),             QLatin1String("PNG"));
     imageSetAttribute(QLatin1String("originalColorModel"), colorModel);
     imageSetAttribute(QLatin1String("originalBitDepth"),   bit_depth);
     imageSetAttribute(QLatin1String("originalSize"),       QSize(width, height));
 
     return true;
 }
 
 } // namespace DigikamPNGDImgPlugin