pub fn write_jpeg(
path: impl AsRef<Path>,
width: u32,
height: u32,
pixels: &[u8],
quality: u8,
background: Color,
) -> Result<()>Available on crate feature
jpeg only.Expand description
Write pixels (RGBA8 with straight alpha, length width * height * 4) to
path as a JPEG.
See write_jpeg_to for how quality and background are treated.
Examples found in repository?
examples/image_formats.rs (line 85)
35fn main() {
36 let (w, h) = (900u32, 500u32);
37 let dpi = 96.0;
38
39 let comp = || Composition::empty(1, 1).place(1, 1, Span::cell(), Patch::new("panel"));
40
41 let xs: Vec<f64> = (0..60).map(|i| i as f64 * 1.7).collect();
42 let ys: Vec<f64> = xs
43 .iter()
44 .map(|x| 50.0 + 25.0 * (x * 0.07).sin() - 0.15 * x)
45 .collect();
46
47 let mut plot = Plot::new(&comp(), "panel").bind("x", "x").bind("y", "y");
48 plot.add_geom(
49 PointGeom::builder()
50 .set("x", xs)
51 .set("y", ys)
52 .set("fill", rgb8(70, 120, 220))
53 .set("size", 6.0_f64)
54 .build(),
55 );
56 plot.set_title("One render, four formats");
57 plot.add_axis(Axis::rail("x", AxisPlacement::Cartesian(AxisSide::Bottom)));
58 plot.add_axis(Axis::rail("y", AxisPlacement::Cartesian(AxisSide::Left)));
59
60 let mut view = PlotComposition::new(&comp())
61 .add_scale("x", scale::continuous(0.0..=100.0))
62 .add_scale("y", scale::continuous(20.0..=80.0))
63 .with_plot(plot);
64
65 let mut renderer = VelloRenderer::new().expect("vello renderer init");
66 {
67 let scene = renderer.scene();
68 scene.clear();
69 view.render(scene, Size::new(w as f64, h as f64), dpi);
70 }
71
72 let mut pixels = vec![0u8; (w * h * 4) as usize];
73 renderer
74 .render_to_buffer(w, h, TRANSPARENT, &mut pixels)
75 .expect("render");
76
77 let dir = std::env::current_dir().unwrap().join("examples");
78 let png = dir.join("image_formats.png");
79 let jpg = dir.join("image_formats.jpg");
80 let tif = dir.join("image_formats.tiff");
81 let webp = dir.join("image_formats.webp");
82
83 write_png(&png, w, h, &pixels).expect("write png");
84 // Quality 90, composited onto the light background the plot theme assumes.
85 write_jpeg(&jpg, w, h, &pixels, 90, rgb8(248, 248, 252)).expect("write jpeg");
86 write_tiff(&tif, w, h, &pixels, TiffCompression::Deflate).expect("write tiff");
87 write_webp(&webp, w, h, &pixels).expect("write webp");
88
89 for path in [&png, &jpg, &tif, &webp] {
90 let bytes = std::fs::metadata(path).expect("stat").len();
91 println!(
92 "wrote {} ({:.1} KiB)",
93 path.display(),
94 bytes as f64 / 1024.0
95 );
96 }
97}