fparkan/vendor/exr/examples/7_crop_alpha_any_image.rs
Valentin Popov 1b6a04ca55
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
2024-01-08 01:21:28 +04:00

47 lines
1.6 KiB
Rust

extern crate image as png;
extern crate exr;
/// Read an arbitrary image, crop away transparent pixels,
/// then write the cropped result to another file.
pub fn main() {
use exr::prelude::*;
let path = "tests/images/valid/custom/oh crop.exr";
// loads any image (excluding deep data)
let image: FlatImage = read_all_flat_layers_from_file(path)
.expect("this file exists in the exrs repository. download that?");
// construct a cropped image
let image = Image {
attributes: image.attributes,
// crop each layer
layer_data: image.layer_data.into_iter().map(|layer|{
println!("cropping layer {:#?}", layer);
// find the alpha channel of the layer
let alpha_channel_index = layer.channel_data.list.iter()
.position(|channel| channel.name.eq_case_insensitive("A"));
// if has alpha, crop it where alpha is zero
if let Some(alpha_channel_index) = alpha_channel_index {
layer.crop_where(|pixel: FlatSamplesPixel| pixel[alpha_channel_index].is_zero())
.or_crop_to_1x1_if_empty() // do not remove empty layers from image, because it could result in an image without content
.reallocate_cropped() // actually perform the crop operation
}
else {
// return the original layer, as no alpha channel can be used for cropping
layer
}
}).collect::<Layers<_>>(),
};
image.write().to_file("cropped.exr").unwrap();
println!("cropped file to cropped.exr");
}