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authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/jpeg-decoder/examples
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/jpeg-decoder/examples')
-rw-r--r--vendor/jpeg-decoder/examples/decode.rs83
1 files changed, 83 insertions, 0 deletions
diff --git a/vendor/jpeg-decoder/examples/decode.rs b/vendor/jpeg-decoder/examples/decode.rs
new file mode 100644
index 0000000..13934fe
--- /dev/null
+++ b/vendor/jpeg-decoder/examples/decode.rs
@@ -0,0 +1,83 @@
+extern crate jpeg_decoder as jpeg;
+extern crate png;
+
+use std::env;
+use std::fs::File;
+use std::io::{self, BufReader, Write};
+use std::process;
+
+fn usage() -> ! {
+ write!(io::stderr(), "usage: decode image.jpg image.png").unwrap();
+ process::exit(1)
+}
+
+fn main() {
+ let mut args = env::args().skip(1);
+ let input_path = args.next().unwrap_or_else(|| usage());
+ let output_path = args.next().unwrap_or_else(|| usage());
+
+ let input_file = File::open(input_path).expect("The specified input file could not be opened");
+ let mut decoder = jpeg::Decoder::new(BufReader::new(input_file));
+ let mut data = decoder.decode().expect("Decoding failed. If other software can successfully decode the specified JPEG image, then it's likely that there is a bug in jpeg-decoder");
+ let info = decoder.info().unwrap();
+
+ eprintln!("{:?}", info);
+ eprintln!("Exif: {}", decoder.exif_data().is_some());
+ eprintln!("ICC: {}", decoder.icc_profile().is_some());
+
+ let output_file = File::create(output_path).unwrap();
+ let mut encoder = png::Encoder::new(output_file, info.width as u32, info.height as u32);
+
+ match info.pixel_format {
+ jpeg::PixelFormat::L16 => {
+ encoder.set_depth(png::BitDepth::Sixteen);
+ encoder.set_color(png::ColorType::Grayscale);
+ },
+ jpeg::PixelFormat::RGB24 => {
+ encoder.set_depth(png::BitDepth::Eight);
+ encoder.set_color(png::ColorType::RGB);
+ },
+ jpeg::PixelFormat::CMYK32 => {
+ data = cmyk_to_rgb(&mut data);
+ encoder.set_depth(png::BitDepth::Eight);
+ encoder.set_color(png::ColorType::RGB)
+ },
+ jpeg::PixelFormat::L8 => {
+ encoder.set_depth(png::BitDepth::Eight);
+ encoder.set_color(png::ColorType::Grayscale);
+ },
+ }
+
+ encoder.write_header()
+ .expect("writing png header failed")
+ .write_image_data(&data)
+ .expect("png encoding failed");
+}
+
+fn cmyk_to_rgb(input: &[u8]) -> Vec<u8> {
+ let size = input.len() - input.len() / 4;
+ let mut output = Vec::with_capacity(size);
+
+ for pixel in input.chunks(4) {
+ let c = pixel[0] as f32 / 255.0;
+ let m = pixel[1] as f32 / 255.0;
+ let y = pixel[2] as f32 / 255.0;
+ let k = pixel[3] as f32 / 255.0;
+
+ // CMYK -> CMY
+ let c = c * (1.0 - k) + k;
+ let m = m * (1.0 - k) + k;
+ let y = y * (1.0 - k) + k;
+
+ // CMY -> RGB
+ let r = (1.0 - c) * 255.0;
+ let g = (1.0 - m) * 255.0;
+ let b = (1.0 - y) * 255.0;
+
+ output.push(r as u8);
+ output.push(g as u8);
+ output.push(b as u8);
+ }
+
+ output
+}