From 7713e4e0bd4726da823f50309dce80ef9cf17d32 Mon Sep 17 00:00:00 2001 From: Rich Geldreich Date: Mon, 19 Jan 2026 14:10:01 -0500 Subject: [PATCH] Update README.md --- README.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/README.md b/README.md index 14b424c..b69e0c0 100644 --- a/README.md +++ b/README.md @@ -264,6 +264,8 @@ basisu -hdr_6x6i -lambda 500 x.exr 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. 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](https://en.wikipedia.org/wiki/Candela_per_square_metre) (candelas per square meter). 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`.