AgX-default_contrast.lut.png to vertical exr

main.rs

// for converting https://github.com/MrLixm/AgXc/blob/main/obs/obs-script/AgX-default_contrast.lut.png
// to a vertical exr

// [dependencies]
// image = "0.24"
// glam = "0.22"

use std::path::Path;

use image::{DynamicImage, GenericImage, GenericImageView, ImageBuffer, Rgb};
extern crate image;

fn main() {
    let binding = image::open(Path::new("AgX-default_contrast.lut.png")).unwrap();
    let im = binding.as_rgb16().unwrap();

    let block_size = im.height();

    let mut imgbuf: ImageBuffer<Rgb<f32>, Vec<f32>> =
        image::ImageBuffer::new(im.height(), im.width());

    // rearrange into vertical blocks
    for i in 0..block_size {
        let view = DynamicImage::ImageRgb16(
            im.view(i * block_size, 0, block_size, block_size)
                .to_image(),
        );

        let mut f32_image = view.clone().into_rgb32f();

        for (f32sample, u16sample) in f32_image
            .iter_mut()
            .zip(view.as_flat_samples_u16().unwrap().samples)
        {
            // Convert from u16 to f32 and apply cctf decoding
            *f32sample = ((*u16sample as f64) / u16::MAX as f64).powf(2.2) as f32;
        }

        imgbuf.copy_from(&f32_image, 0, i * block_size).unwrap();
    }

    imgbuf
        .save(Path::new("AgX-default_contrast_vert.lut.exr"))
        .unwrap();
}