File indexing completed on 2025-01-19 03:57:41

 /* ============================================================
  *
  * This file is a part of digiKam
  *
  * Date        : 2012-01-03
  * Description : Calculates the TanTriggs Preprocessing as described in:
  *               Tan, X., and Triggs, B. "Enhanced local texture feature sets for face
  *               recognition under difficult lighting conditions.". IEEE Transactions
  *               on Image Processing 19 (2010), 1635–650.
  *               Default parameters are taken from the paper.
  *
  * SPDX-FileCopyrightText: 2012-2013 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
  * SPDX-FileCopyrightText:      2012 Philipp Wagner <bytefish at gmx dot de>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ============================================================ */
 
 #ifndef DIGIKAM_TAN_TRIGGS_PREPROCESSOR_H
 #define DIGIKAM_TAN_TRIGGS_PREPROCESSOR_H
 
 // Locak includes
 
 #include "digikam_opencv.h"
 
 namespace Digikam
 {
 
 class TanTriggsPreprocessor
 {
 public:
 
     explicit TanTriggsPreprocessor();
 
     /**
      * Performs the Tan Triggs preprocessing to reduce the influence of lightning conditions.
      * Returns a grey-scale 8-bit image.
      */
     cv::Mat preprocess(const cv::Mat& inputImage);
 
     /**
      * Performs the Tan Triggs preprocessing to reduce the influence of lightning conditions.
      * Expects a one-channel image.
      * Returns a one-channel floating point (CV_32F1) image.
      */
     cv::Mat preprocessRaw(const cv::Mat& inputImage);
 
     /**
      * Converts CV_32F1 -> CV_8UC1
      */
     cv::Mat normalize(const cv::Mat& preprocessedImage);
 
 public:
 
     /// Parameters, initialized with the default values from the paper.
     float alpha;
     float tau;
     float gamma;
     float sigma0;
     float sigma1;
 };
 
 } // namespace Digikam
 
 #endif // DIGIKAM_TAN_TRIGGS_PREPROCESSOR_H