diff options
Diffstat (limited to 'vendor/exr/examples/2_rgba_adjust_exposure.rs')
| -rw-r--r-- | vendor/exr/examples/2_rgba_adjust_exposure.rs | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/vendor/exr/examples/2_rgba_adjust_exposure.rs b/vendor/exr/examples/2_rgba_adjust_exposure.rs new file mode 100644 index 0000000..c4e6097 --- /dev/null +++ b/vendor/exr/examples/2_rgba_adjust_exposure.rs @@ -0,0 +1,80 @@ + +// exr imports +extern crate exr; + +/// Read an rgba image, increase the exposure, and then write it back. +/// Uses multi-core compression where appropriate. +/// +/// All non-rgba channels and all layers except the first rgba layers will not be present in the new file. +fn main() { + use exr::prelude::*; + + /// This is an example of a custom image type. + /// You use your own image struct here. + // This struct trades sub-optimal memory-efficiency for clarity, + // because this is an example, and does not have to be perfectly efficient. + #[derive(Debug, PartialEq)] + struct CustomPixels { lines: Vec<Vec<RgbaF32Pixel>> } + type RgbaF32Pixel = (f32, f32, f32, f32); + + // read the image from a file + let mut image = read().no_deep_data() + .largest_resolution_level() + .rgba_channels( + // create our custom image based on the file info + |resolution, _channels| -> CustomPixels { + let default_rgba_pixel = (0.0, 0.0, 0.0, 0.0); + let default_line = vec![default_rgba_pixel; resolution.width()]; + let lines = vec![default_line; resolution.height()]; + CustomPixels { lines } + }, + + // request pixels with red, green, blue, and optionally and alpha values. + // transfer each pixel from the file to our image + |image, position, (r,g,b,a): RgbaF32Pixel| { + + // insert the values into our custom image + image.lines[position.y()][position.x()] = (r,g,b,a); + } + ) + .first_valid_layer() + .all_attributes() + .from_file("generated_rgba.exr") + .expect("run the `1_write_rgba` example to generate the required file"); + + let exposure_multiplier = 2.0; + + { // increase exposure of all pixels + for line in &mut image.layer_data.channel_data.pixels.lines { + for (r,g,b,_) in line { + // you should probably check the color space and white points + // for high quality color adjustments + *r *= exposure_multiplier; + *g *= exposure_multiplier; + *b *= exposure_multiplier; + } + } + + // also update meta data after modifying the image + if let Some(exposure) = &mut image.layer_data.attributes.exposure { + println!("increased exposure from {}s to {}s", exposure, *exposure * exposure_multiplier); + *exposure *= exposure_multiplier; + } + } + + // enable writing our custom pixel storage to a file + // FIXME this should be passed as a closure to the `write_with(|x| y)` call + impl GetPixel for CustomPixels { + type Pixel = RgbaF32Pixel; + fn get_pixel(&self, position: Vec2<usize>) -> Self::Pixel { + self.lines[position.y()][position.x()] + } + } + + // write the image to a file + image + .write().to_file("rgba_exposure_adjusted.exr") + .unwrap(); + + println!("created file rgba_exposure_adjusted.exr"); +}
\ No newline at end of file |