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extern crate image as png;
extern crate exr;
/// Read an rgba image, or fail if none can be found.
/// Then crop away transparent pixels,
/// and write the cropped result to another file.
/// This retains only the rgb pixels, and no other layers.
pub fn main() {
use exr::prelude::*;
use exr::image::pixel_vec::*; // import predefined pixel storage
let path = "tests/images/valid/custom/oh crop.exr";
type DynamicRgbaPixel = (Sample, Sample, Sample, Sample); // `Sample` is an enum containing the original data type (f16,f32, or u32)
// load an rgba image
// this specific example discards all but the first valid rgb layers and converts all pixels to f32 values
// TODO optional alpha channel!
let image: PixelImage<PixelVec<DynamicRgbaPixel>, RgbaChannels> = read_first_rgba_layer_from_file(
path,
PixelVec::<DynamicRgbaPixel>::constructor,
// use this predefined rgba pixel container from the exr crate, requesting any type of pixels with 3 or 4 values
PixelVec::set_pixel
).expect("this file exists in the exrs repository. download that?");
// construct a ~simple~ cropped image
let image: Image<Layer<CroppedChannels<SpecificChannels<PixelVec<DynamicRgbaPixel>, RgbaChannels>>>> = Image {
attributes: image.attributes,
// crop each layer
layer_data: {
println!("cropping layer {:#?}", image.layer_data);
// if has alpha, crop it where alpha is zero
image.layer_data
.crop_where(|(_r, _g, _b, alpha)| alpha.is_zero())
.or_crop_to_1x1_if_empty() // do not remove empty layers from image, because it could result in an image without content
},
};
image.write().to_file("cropped_rgba.exr").unwrap();
println!("cropped file to cropped_rgba.exr");
}
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