Function peek_info 

pub fn peek_info(data: &[u8], opts: &DecodeOptions) -> Result<ImageInfo>

Parse image headers and return image dimensions/format without decoding pixels.

Detects the image format (JPEG or PNG) from magic bytes and returns an ImageInfo describing the post-decode layout. For images with an EXIF 90°/270° orientation tag and opts.apply_exif == true, width and height reflect the post-rotation dimensions — matching exactly what a subsequent ImageDecoder::decode_into call would write to the tensor.

This is the recommended entry point for one-shot decode flows that need to allocate a tensor sized to the image:

use edgefirst_codec::{peek_info, ImageDecoder, ImageLoad, DecodeOptions};
use edgefirst_tensor::{Tensor, TensorMemory, PixelFormat};

let data = std::fs::read("image.jpg").unwrap();
let opts = DecodeOptions::default().with_format(PixelFormat::Rgba);
let info = peek_info(&data, &opts).unwrap();
let mut tensor = Tensor::<u8>::image(info.width, info.height, info.format,
                                      Some(TensorMemory::Mem)).unwrap();
let mut decoder = ImageDecoder::new();
tensor.load_image(&mut decoder, &data, &opts).unwrap();