fix: Fix some legacy 'Linear' color references (#4959)

Convert to modern oiio color space nomenclature.

Signed-off-by: Larry Gritz <[email protected]>

Author: lgritz

src/dpx.imageio/dpxinput.cpp

@@ -312,9 +312,9 @@ DPXInput::seek_subimage(int subimage, int miplevel)
 
     // image linearity
     switch (m_dpx.header.Transfer(subimage)) {
-    case dpx::kLinear: m_spec.set_colorspace("Linear"); break;
+    case dpx::kLinear: m_spec.set_colorspace("lin_rec709_scene"); break;
     case dpx::kLogarithmic: m_spec.set_colorspace("KodakLog"); break;
-    case dpx::kITUR709: m_spec.set_colorspace("Rec709"); break;
+    case dpx::kITUR709: m_spec.set_colorspace("srgb_rec709_scene"); break;
     case dpx::kUserDefined:
         if (!std::isnan(m_dpx.header.Gamma()) && m_dpx.header.Gamma() != 0) {
             set_colorspace_rec709_gamma(m_spec, float(m_dpx.header.Gamma()));

src/dpx.imageio/dpxoutput.cpp

@@ -12,6 +12,7 @@
 #include "libdpx/DPX.h"
 #include "libdpx/DPXColorConverter.h"
 
+#include <OpenImageIO/color.h>
 #include <OpenImageIO/fmath.h>
 #include <OpenImageIO/imageio.h>
 #include <OpenImageIO/strutil.h>
@@ -435,14 +436,18 @@ DPXOutput::prep_subimage(int s, bool allocate)
     m_desc = get_image_descriptor();
 
     // transfer function
+    const ColorConfig& colorconfig = ColorConfig::default_colorconfig();
     std::string colorspace = spec_s.get_string_attribute("oiio:ColorSpace", "");
-    if (Strutil::iequals(colorspace, "Linear"))
+    if (colorconfig.equivalent(colorspace, "lin_rec709_scene"))
         m_transfer = dpx::kLinear;
-    else if (Strutil::istarts_with(colorspace, "Gamma"))
-        m_transfer = dpx::kUserDefined;
-    else if (Strutil::iequals(colorspace, "Rec709"))
+    else if (colorconfig.equivalent(colorspace, "srgb_rec709_scene"))
         m_transfer = dpx::kITUR709;
-    else if (Strutil::iequals(colorspace, "KodakLog"))
+    else if (colorconfig.equivalent(colorspace, "g22_rec709_scene")
+             || colorconfig.equivalent(colorspace, "g24_rec709_scene")
+             || colorconfig.equivalent(colorspace, "g18_rec709_scene")
+             || Strutil::istarts_with(colorspace, "Gamma"))
+        m_transfer = dpx::kUserDefined;
+    else if (colorconfig.equivalent(colorspace, "KodakLog"))
         m_transfer = dpx::kLogarithmic;
     else {
         std::string dpxtransfer = spec_s.get_string_attribute("dpx:Transfer",

testsuite/python-imagebufalgo/src/test_imagebufalgo.py

@@ -374,9 +374,9 @@ def test_iba (func: Callable[..., oiio.ImageBuf], *args, **kwargs) -> oiio.Image
     b.setpixel(0, 1, (.5,.5,.5,1))
     b.setpixel(1, 1, (1,1,1,1))
     dumpimg (b, msg="linear src=")
-    r = test_iba (ImageBufAlgo.colorconvert, b, "Linear", "sRGB")
+    r = test_iba (ImageBufAlgo.colorconvert, b, "lin_rec709", "sRGB")
     dumpimg (r, msg="to srgb =")
-    r = ImageBufAlgo.colorconvert(r, "sRGB", "Linear")
+    r = ImageBufAlgo.colorconvert(r, "sRGB", "lin_rec709")
     dumpimg (r, msg="back to linear =")
     # Just to test, make a matrix that halves red, doubles green,
     # adds 0.1 to blue.