butteraugli_main and benchmark_xl: higher default intensity target fo…

…r HDR input (libjxl#3870) (cherry picked from commit 42422b4)
libsdl-org · Nov 26, 2024 · 7ccdcf8 · 7ccdcf8
1 parent 69d1ed1
commit 7ccdcf8
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Showing 2 changed files with 18 additions and 7 deletions.
diff --git a/tools/benchmark/benchmark_xl.cc b/tools/benchmark/benchmark_xl.cc
@@ -267,11 +267,14 @@ Status DoCompress(const std::string& filename, const PackedPixelFile& ppf,
     const ImageBundle& ib2 = ppf2_io.Main();
     if (jxl::SameSize(ppf, ppf2)) {
       ButteraugliParams params;
-      // Hack the default intensity target value to be 80.0, the intensity
-      // target of sRGB images and a more reasonable viewing default than
-      // JPEG XL file format's default.
+      // Hack the default intensity target value for SDR images to be 80.0, the
+      // intensity target of sRGB images and a more reasonable viewing default
+      // than JPEG XL file format's default.
       // TODO(szabadka) Support different intensity targets as well.
-      params.intensity_target = 80.0;
+      const auto& transfer_function = ib1.c_current().Tf();
+      params.intensity_target = transfer_function.IsPQ()    ? 10000.f
+                                : transfer_function.IsHLG() ? 1000.f
+                                                            : 80.f;
 
       const JxlCmsInterface& cms = *JxlGetDefaultCms();
       JxlButteraugliComparator comparator(params, cms);

diff --git a/tools/butteraugli_main.cc b/tools/butteraugli_main.cc
@@ -99,7 +99,15 @@ Status RunButteraugli(const char* pathname1, const char* pathname2,
   ButteraugliParams butteraugli_params;
   butteraugli_params.hf_asymmetry = 1.0f;
   butteraugli_params.xmul = 1.0f;
-  butteraugli_params.intensity_target = intensity_target;
+  if (intensity_target > 0) {
+    butteraugli_params.intensity_target = intensity_target;
+  } else {
+    const auto& transfer_function = io1.Main().c_current().Tf();
+    butteraugli_params.intensity_target = transfer_function.IsPQ() ? 10000.f
+                                          : transfer_function.IsHLG()
+                                              ? 1000.f
+                                              : 80.f;  // sRGB intensity target.
+  }
   const JxlCmsInterface& cms = *JxlGetDefaultCms();
   JxlButteraugliComparator comparator(butteraugli_params, cms);
   float distance;
@@ -146,15 +154,15 @@ int main(int argc, char** argv) {
             " without attached profiles (such as ppm or pfm) are interpreted"
             " as nonlinear sRGB. The hint format is RGB_D65_SRG_Rel_Lin for"
             " linear sRGB. Intensity target is viewing conditions screen nits"
-            ", defaults to 80.\n",
+            ", defaults to 80 for SDR input.\n",
             argv[0]);
     return 1;
   }
   std::string distmap;
   std::string raw_distmap;
   std::string colorspace;
   double p = 3;
-  float intensity_target = 80.0;  // sRGB intensity target.
+  float intensity_target = 0.f;
   for (int i = 3; i < argc; i++) {
     if (std::string(argv[i]) == "--distmap" && i + 1 < argc) {
       distmap = argv[++i];