Merge pull request #174 from jrmuizel/icc

Add support for extracting the ICC profile.

Author: HeroicKatora

src/decoder.rs

@@ -3,7 +3,8 @@ use error::{Error, Result, UnsupportedFeature};
 use huffman::{fill_default_mjpeg_tables, HuffmanDecoder, HuffmanTable};
 use marker::Marker;
 use parser::{AdobeColorTransform, AppData, CodingProcess, Component, Dimensions, EntropyCoding, FrameInfo,
-             parse_app, parse_com, parse_dht, parse_dqt, parse_dri, parse_sof, parse_sos, ScanInfo};
+             parse_app, parse_com, parse_dht, parse_dqt, parse_dri, parse_sof, parse_sos, IccChunk,
+             ScanInfo};
 use upsampler::Upsampler;
 use std::cmp;
 use std::io::Read;
@@ -72,6 +73,8 @@ pub struct Decoder<R> {
     is_jfif: bool,
     is_mjpeg: bool,
 
+    icc_markers: Vec<IccChunk>,
+
     // Used for progressive JPEGs.
     coefficients: Vec<Vec<i16>>,
     // Bitmask of which coefficients has been completely decoded.
@@ -91,6 +94,7 @@ impl<R: Read> Decoder<R> {
             color_transform: None,
             is_jfif: false,
             is_mjpeg: false,
+            icc_markers: Vec::new(),
             coefficients: Vec::new(),
             coefficients_finished: [0; MAX_COMPONENTS],
         }
@@ -120,6 +124,39 @@ impl<R: Read> Decoder<R> {
         }
     }
 
+    /// Returns the embeded icc profile if the image contains one.
+    pub fn icc_profile(&self) -> Option<Vec<u8>> {
+        let mut marker_present: [Option<&IccChunk>; 256] = [None; 256];
+        let num_markers = self.icc_markers.len();
+        if num_markers == 0 && num_markers < 256 {
+            return None;
+        }
+        // check the validity of the markers
+        for chunk in &self.icc_markers {
+            if usize::from(chunk.num_markers) != num_markers {
+                // all the lengths must match
+                return None;
+            }
+            if chunk.seq_no == 0 {
+                return None;
+            }
+            if marker_present[usize::from(chunk.seq_no)].is_some() {
+                // duplicate seq_no
+                return None;
+            } else {
+                marker_present[usize::from(chunk.seq_no)] = Some(chunk);
+            }
+        }
+
+        // assemble them together by seq_no failing if any are missing
+        let mut data = Vec::new();
+        // seq_no's start at 1
+        for &chunk in marker_present.get(1..=num_markers)? {
+            data.extend_from_slice(&chunk?.data);
+        }
+        Some(data)
+    }
+
     /// Tries to read metadata from the image without decoding it.
     ///
     /// If successful, the metadata can be obtained using the `info` method.
@@ -336,6 +373,7 @@ impl<R: Read> Decoder<R> {
                                 self.is_jfif = true;
                             },
                             AppData::Avi1 => self.is_mjpeg = true,
+                            AppData::Icc(icc) => self.icc_markers.push(icc),
                         }
                     }
                 },

src/parser.rs

@@ -70,6 +70,7 @@ pub enum AppData {
     Adobe(AdobeColorTransform),
     Jfif,
     Avi1,
+    Icc(IccChunk),
 }
 
 // http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#Adobe
@@ -81,6 +82,12 @@ pub enum AdobeColorTransform {
     // YCbCrK
     YCCK,
 }
+#[derive(Debug)]
+pub struct IccChunk {
+    pub num_markers: u8,
+    pub seq_no: u8,
+    pub data: Vec<u8>,
+}
 
 impl FrameInfo {
     pub(crate) fn update_idct_size(&mut self, idct_size: usize) -> Result<()> {
@@ -554,7 +561,27 @@ pub fn parse_app<R: Read>(reader: &mut R, marker: Marker) -> Result<Option<AppDa
                     result = Some(AppData::Avi1);
                 }
             }
-        },
+        }
+        APP(2) => {
+            if length > 14 {
+                let mut buffer = [0u8; 14];
+                reader.read_exact(&mut buffer)?;
+                bytes_read = buffer.len();
+
+                // http://www.color.org/ICC_Minor_Revision_for_Web.pdf
+                // B.4 Embedding ICC profiles in JFIF files
+                if &buffer[0..12] == b"ICC_PROFILE\0" {
+                    let mut data = vec![0; length - bytes_read];
+                    reader.read_exact(&mut data)?;
+                    bytes_read += data.len();
+                    result = Some(AppData::Icc(IccChunk {
+                        seq_no: buffer[12],
+                        num_markers: buffer[13],
+                        data,
+                    }));
+                }
+            }
+        }
         APP(14) => {
             if length >= 12 {
                 let mut buffer = [0u8; 12];

tests/lib.rs

@@ -26,3 +26,19 @@ fn read_info() {
     assert_eq!(info, ref_info);
     assert_eq!(data, ref_data);
 }
+
+#[test]
+fn read_icc_profile() {
+    let path = Path::new("tests")
+        .join("reftest")
+        .join("images")
+        .join("mozilla")
+        .join("jpg-srgb-icc.jpg");
+
+    let mut decoder = jpeg::Decoder::new(File::open(&path).unwrap());
+    decoder.decode().unwrap();
+
+    let profile = decoder.icc_profile().unwrap();
+    // "acsp" is a mandatory string in ICC profile headers.
+    assert_eq!(&profile[36..40], b"acsp");
+}