apply correct normalization factor during decode

Test: ./ultrahdr_unit_test
ittiam-systems · Oct 31, 2024 · 990f103 · 990f103
1 parent 613fee1
commit 990f103
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Showing 2 changed files with 10 additions and 6 deletions.
diff --git a/lib/src/gpu/applygainmap_gl.cpp b/lib/src/gpu/applygainmap_gl.cpp
@@ -136,13 +136,13 @@ static const std::string applyGainMapShader = R"__SHADER__(
   uniform float logMinBoost;
   uniform float logMaxBoost;
   uniform float weight;
-  uniform float displayBoost;
+  uniform float normalize;
 
   float applyGainMapSample(const float channel, float gain) {
     gain = pow(gain, 1.0f / gamma);
     float logBoost = logMinBoost * (1.0f - gain) + logMaxBoost * gain;
     logBoost = exp2(logBoost * weight);
-    return channel * logBoost / displayBoost;
+    return channel * logBoost / normalize;
   }
 
   vec3 applyGain(const vec3 color, const vec3 gain) {
@@ -317,7 +317,7 @@ uhdr_error_info_t applyGainMapGLES(uhdr_raw_image_t* sdr_intent, uhdr_raw_image_
   GLint logMinBoostLocation = glGetUniformLocation(shaderProgram, "logMinBoost");
   GLint logMaxBoostLocation = glGetUniformLocation(shaderProgram, "logMaxBoost");
   GLint weightLocation = glGetUniformLocation(shaderProgram, "weight");
-  GLint displayBoostLocation = glGetUniformLocation(shaderProgram, "displayBoost");
+  GLint normalizeLocation = glGetUniformLocation(shaderProgram, "normalize");
 
   glUniform1i(pWidthLocation, sdr_intent->w);
   glUniform1i(pHeightLocation, sdr_intent->h);
@@ -335,7 +335,10 @@ uhdr_error_info_t applyGainMapGLES(uhdr_raw_image_t* sdr_intent, uhdr_raw_image_
     gainmap_weight = 1.0f;
   }
   glUniform1f(weightLocation, gainmap_weight);
-  glUniform1f(displayBoostLocation, display_boost);
+  float normalize = 1.0f;
+  if (output_ct == UHDR_CT_HLG) normalize = kHlgMaxNits / kSdrWhiteNits;
+  else if (output_ct == UHDR_CT_PQ) normalize = kPqMaxNits / kSdrWhiteNits;
+  glUniform1f(normalizeLocation, normalize);
 
   glActiveTexture(GL_TEXTURE0);
   glBindTexture(GL_TEXTURE_2D, yuvTexture);

diff --git a/lib/src/jpegr.cpp b/lib/src/jpegr.cpp
@@ -1477,7 +1477,7 @@ uhdr_error_info_t JpegR::applyGainMap(uhdr_raw_image_t* sdr_intent, uhdr_raw_ima
 
   JobQueue jobQueue;
   std::function<void()> applyRecMap = [sdr_intent, gainmap_img, dest, &jobQueue, &idwTable,
-                                       output_ct, &gainLUT, display_boost,
+                                       output_ct, &gainLUT,
 #if !USE_APPLY_GAIN_LUT
                                        gainmap_metadata, gainmap_weight,
 #endif
@@ -1530,7 +1530,6 @@ uhdr_error_info_t JpegR::applyGainMap(uhdr_raw_image_t* sdr_intent, uhdr_raw_ima
 #endif
           }
 
-          rgb_hdr = rgb_hdr / display_boost;
           size_t pixel_idx = x + y * dest->stride[UHDR_PLANE_PACKED];
 
           switch (output_ct) {
@@ -1545,6 +1544,7 @@ uhdr_error_info_t JpegR::applyGainMap(uhdr_raw_image_t* sdr_intent, uhdr_raw_ima
 #else
               ColorTransformFn hdrOetf = hlgOetf;
 #endif
+              rgb_hdr = rgb_hdr * kSdrWhiteNits / kHlgMaxNits;
               rgb_hdr = hlgInverseOotfApprox(rgb_hdr);
               Color rgb_gamma_hdr = hdrOetf(rgb_hdr);
               uint32_t rgba_1010102 = colorToRgba1010102(rgb_gamma_hdr);
@@ -1558,6 +1558,7 @@ uhdr_error_info_t JpegR::applyGainMap(uhdr_raw_image_t* sdr_intent, uhdr_raw_ima
 #else
               ColorTransformFn hdrOetf = pqOetf;
 #endif
+              rgb_hdr = rgb_hdr * kSdrWhiteNits / kPqMaxNits;
               Color rgb_gamma_hdr = hdrOetf(rgb_hdr);
               uint32_t rgba_1010102 = colorToRgba1010102(rgb_gamma_hdr);
               reinterpret_cast<uint32_t*>(dest->planes[UHDR_PLANE_PACKED])[pixel_idx] =