Merge pull request #1230 from HeroicKatora/pbm-rgba-decoding-1226

Fix PBM ascii decoding
image-rs · May 28, 2020 · 092db1e · 092db1e
2 parents 1b279e2 + 2e86692
commit 092db1e
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Showing 2 changed files with 19 additions and 3 deletions.
diff --git a/src/pnm/decoder.rs b/src/pnm/decoder.rs
@@ -736,7 +736,7 @@ impl Sample for PbmBit {
         let count = (width*height*samples) as usize;
         let raw_samples = reader.bytes()
             .filter_map(|ascii| match ascii {
-                Ok(b'0') => Some(Ok(1)),
+                Ok(b'0') => Some(Ok(255)),
                 Ok(b'1') => Some(Ok(0)),
                 Err(err) => Some(Err(ImageError::IoError(err))),
                 Ok(b'\t')
@@ -1096,7 +1096,7 @@ ENDHDR
 
         let mut image = vec![0; decoder.total_bytes() as usize];
         decoder.read_image(&mut image).unwrap();
-        assert_eq!(image, vec![1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0]);
+        assert_eq!(image, vec![255, 0, 0, 255, 0, 0, 0, 255, 0, 0, 255, 0]);
         match PnmDecoder::new(&pbmbinary[..]).unwrap().into_inner() {
             (
                 _,
@@ -1128,7 +1128,7 @@ ENDHDR
 
         let mut image = vec![0; decoder.total_bytes() as usize];
         decoder.read_image(&mut image).unwrap();
-        assert_eq!(image, vec![1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0]);
+        assert_eq!(image, vec![255, 0, 0, 255, 0, 0, 0, 255, 0, 0, 255, 0]);
         match PnmDecoder::new(&pbmbinary[..]).unwrap().into_inner() {
             (
                 _,

diff --git a/src/pnm/mod.rs b/src/pnm/mod.rs
@@ -108,6 +108,22 @@ mod tests {
         assert_eq!(loaded_image, buffer_u8);
     }
 
+    #[test]
+    fn roundtrip_gray() {
+        #[rustfmt::skip]
+        let buf: [u8; 16] = [
+            0, 0, 0, 255,
+            255, 255, 255, 255,
+            255, 0, 255, 0,
+            255, 0, 0, 0,
+        ];
+
+        execute_roundtrip_default(&buf, 4, 4, ColorType::L8);
+        execute_roundtrip_with_subtype(&buf, 4, 4, ColorType::L8, PNMSubtype::ArbitraryMap);
+        execute_roundtrip_with_subtype(&buf, 4, 4, ColorType::L8, PNMSubtype::Graymap(SampleEncoding::Ascii));
+        execute_roundtrip_with_subtype(&buf, 4, 4, ColorType::L8, PNMSubtype::Graymap(SampleEncoding::Binary));
+    }
+
     #[test]
     fn roundtrip_rgb() {
         #[rustfmt::skip]