Update README.md

This commit is contained in:
Rich Geldreich
2026-01-30 15:01:24 -05:00
committed by GitHub
parent 0cc4120dc9
commit a5df671abb

View File

@@ -299,7 +299,7 @@ basisu -hdr_6x6i_level 5 -lambda 500 x.exr
Note the unified `-quality` and `-effort` options work in HDR, too. These examples use the older non-unified options, which allow more direct/precise control.
Be aware that the .EXR reader we're using is [TinyEXR's](https://github.com/syoyo/tinyexr), which doesn't support all possible .EXR compression modes. Tools like [ImageMagick](https://imagemagick.org/) can be used to create .EXR files that TinyEXR can read.
Be aware that the .EXR reader we use is [TinyEXR's](https://github.com/syoyo/tinyexr), which doesn't support all possible .EXR compression modes. Tools like [ImageMagick](https://imagemagick.org/) can be used to create .EXR files that TinyEXR can read.
Alternatively, LDR images (such as .PNG) can be compressed to an HDR format by specifying `-hdr`, `-hdr_6x6`, or `-hdr_6x6i`. By default LDR images, when compressed to an HDR format, are first upconverted to HDR by converting them from sRGB to linear light and scaled to 100 [nits - candela per sq. meter, cd/m²](https://grokipedia.com/page/Candela_per_square_metre). The sRGB conversion step can be disabled by specifying `-hdr_ldr_no_srgb_to_linear`, and the normalized RGB linear light to nit multiplier can be changed by specifying `-hdr_ldr_upconversion_nit_multiplier X`.