Apply orientation transformation based on EXIF data

components/imageproc/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 serde = { version = "1", features = ["derive"] }
+kamadak-exif = "0.5.4"
 
 errors = { path = "../errors" }
 utils = { path = "../utils" }

components/imageproc/src/lib.rs

@@ -10,6 +10,7 @@ use image::error::ImageResult;
 use image::io::Reader as ImgReader;
 use image::{imageops::FilterType, EncodableLayout};
 use image::{ImageFormat, ImageOutputFormat};
+use libs::image::DynamicImage;
 use libs::{image, once_cell, rayon, regex, svg_metadata, webp};
 use once_cell::sync::Lazy;
 use rayon::prelude::*;
@@ -319,6 +320,8 @@ impl ImageOp {
             None => img,
         };
 
+        let img = fix_orientation(&img, &self.input_path).unwrap_or(img);
+
         let mut f = File::create(target_path)?;
 
         match self.format {
@@ -343,6 +346,30 @@ impl ImageOp {
     }
 }
 
+/// Apply image rotation based on EXIF data
+/// Returns `None` if no transformation is needed
+pub fn fix_orientation(img: &DynamicImage, path: &Path) -> Option<DynamicImage> {
+    let file = std::fs::File::open(path).ok()?;
+    let mut buf_reader = std::io::BufReader::new(&file);
+    let exif_reader = exif::Reader::new();
+    let exif = exif_reader.read_from_container(&mut buf_reader).ok()?;
+    let orientation = exif.get_field(exif::Tag::Orientation, exif::In::PRIMARY)?.value.get_uint(0)?;
+    match orientation {
+        // Values are taken from the page 30 of
+        // https://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf
+        // For more details check http://sylvana.net/jpegcrop/exif_orientation.html
+        1 => None,
+        2 => Some(img.fliph()),
+        3 => Some(img.rotate180()),
+        4 => Some(img.flipv()),
+        5 => Some(img.fliph().rotate270()),
+        6 => Some(img.rotate90()),
+        7 => Some(img.fliph().rotate90()),
+        8 => Some(img.rotate270()),
+        _ => None,
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize, PartialEq, Eq)]
 pub struct EnqueueResponse {
     /// The final URL for that asset

components/imageproc/tests/resize_image.rs

@@ -2,7 +2,8 @@ use std::env;
 use std::path::{PathBuf, MAIN_SEPARATOR as SLASH};
 
 use config::Config;
-use imageproc::{assert_processed_path_matches, ImageMetaResponse, Processor};
+use imageproc::{assert_processed_path_matches, fix_orientation, ImageMetaResponse, Processor};
+use libs::image::{self, DynamicImage, GenericImageView, Pixel};
 use libs::once_cell::sync::Lazy;
 
 static CONFIG: &str = r#"
@@ -153,4 +154,75 @@ fn read_image_metadata_webp() {
     );
 }
 
+#[test]
+fn fix_orientation_test() {
+    fn load_img_and_fix_orientation(img_name: &str) -> DynamicImage {
+        let path = TEST_IMGS.join(img_name);
+        let img = image::open(&path).unwrap();
+        fix_orientation(&img, &path).unwrap_or(img)
+    }
+
+    let img = image::open(TEST_IMGS.join("exif_1.jpg")).unwrap();
+    assert!(check_img(img));
+    assert!(check_img(load_img_and_fix_orientation("exif_0.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_1.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_2.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_3.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_4.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_5.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_6.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_7.jpg")));
+    assert!(check_img(load_img_and_fix_orientation("exif_8.jpg")));
+}
+
+#[test]
+fn resize_image_applies_exif_rotation() {
+    // No exif metadata
+    assert!(resize_and_check("exif_0.jpg"));
+    // 1: Horizontal (normal)
+    assert!(resize_and_check("exif_1.jpg"));
+    // 2: Mirror horizontal
+    assert!(resize_and_check("exif_2.jpg"));
+    // 3: Rotate 180
+    assert!(resize_and_check("exif_3.jpg"));
+    // 4: Mirror vertical
+    assert!(resize_and_check("exif_4.jpg"));
+    // 5: Mirror horizontal and rotate 270 CW
+    assert!(resize_and_check("exif_5.jpg"));
+    // 6: Rotate 90 CW
+    assert!(resize_and_check("exif_6.jpg"));
+    // 7: Mirror horizontal and rotate 90 CW
+    assert!(resize_and_check("exif_7.jpg"));
+    // 8: Rotate 270 CW
+    assert!(resize_and_check("exif_8.jpg"));
+}
+
+fn resize_and_check(source_img: &str) -> bool {
+    let source_path = TEST_IMGS.join(source_img);
+    let tmpdir = tempfile::tempdir().unwrap().into_path();
+    let config = Config::parse(CONFIG).unwrap();
+    let mut proc = Processor::new(tmpdir.clone(), &config);
+
+    let resp = proc
+        .enqueue(source_img.into(), source_path, "scale", Some(16), Some(16), "jpg", None)
+        .unwrap();
+
+    proc.do_process().unwrap();
+    let processed_path = PathBuf::from(&resp.static_path);
+    let img = image::open(&tmpdir.join(processed_path)).unwrap();
+    check_img(img)
+}
+
+// Checks that an image has the correct orientation
+fn check_img(img: DynamicImage) -> bool {
+    // top left is red
+    img.get_pixel(0, 0)[0] > 250 // because of the jpeg compression some colors are a bit less than 255
+    // top right is green
+        && img.get_pixel(15, 0)[1] > 250
+    // bottom left is blue
+        && img.get_pixel(0, 15)[2] > 250
+    // bottom right is white
+        && img.get_pixel(15, 15).channels() == [255, 255, 255, 255]
+}
+
 // TODO: Test that hash remains the same if physical path is changed