Function read_header 

pub fn read_header(data: &[u8]) -> Result<JxlImageInfo>

Read image metadata without decoding pixels.

Parses the file header and ICC profile. Returns dimensions, bit depth, orientation, extra channel info, animation info, and color profile.

This is fast (~1μs for sRGB images, ~7μs for images with ICC profiles).

Example

let data = std::fs::read("photo.jxl").unwrap();
let header = zenjxl_decoder::read_header(&data).unwrap();
let (w, h) = header.info.size;
println!("{w}x{h}");