fix(diff): Fix issue when computing perceptual diff #4773

Job	Run time
macos-12 appleclang13/C++17 py3.10 MacOS-12 boost1.76 exr3.1 ocio2.1	32m 15s
macos-13 appleclang14/C++20 py3.11 MacOS-13 boost1.76 exr3.1 ocio2.1	24m 45s
Ubuntu latest releases gcc12 C++17 avx2 exr3.2 ocio2.3	12m 35s
Ubuntu bleeding edge gcc13 C++20 py3.10 OCIO/libtiff/exr-master boost1.74 avx2	12m 15s
windows-2019 VS2019	26m 14s
Ubuntu clang14 C++20 avx2 exr3.1 ocio2.1	14m 28s
VFX2019 gcc6/C++14 py2.7 boost1.66 exr2.4 ocio1.1	11m 4s
Ubuntu debug gcc7/C++14, sse4.2, exr2.4	12m 45s
VFX2020 gcc6/C++14 py3.7 boost1.70 exr2.4 ocio1.1	8m 25s
VFX2021 gcc9/C++17 py3.7 boost1.73 exr2.5 ocio2.0	13m 0s
Ubuntu gcc8 C++17 avx exr2.5	10m 7s
VFX2021 clang10/C++14 avx2 exr2.5 ocio2.0	11m 40s
Ubuntu static libs gcc7 C++14 exr2.4	10m 43s
VFX2022 gcc9/C++17 py39 boost1.76 exr3.1 ocio2.1	11m 30s
VFX2022 clang13/C++17 py39 avx2 exr3.1 ocio2.1	10m 48s
VFX2022 icc/C++17 py3.9 boost1.76 exr3.1 ocio2.1 qt5.15	15m 36s
VFX2022 icx/C++17 py3.9 boost1.76 exr3.1 ocio2.1 qt5.15	14m 21s
VFX2022 sanitizers	30m 37s
VFX2023 gcc11/C++17 py3.10 boost1.80 exr3.1 ocio2.2	12m 18s
VFX2019 oldest/hobbled gcc6.3/C++14 py2.7 boost-1.66 exr-2.4 no-sse no-ocio	11m 34s
VFX2022 clang-format	2m 49s
VFX2023 abi check	8m 58s
	5h 18m 47s

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