Merge remote-tracking branch 'origin/main' into palette-cielab-transparency-lzw

tests/decode_images.rs

@@ -16,7 +16,9 @@ macro_rules! test_image_sum {
         fn $name(file: &str, expected_type: ColorType, expected_sum: $sum_ty) {
             let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
             let img_file = File::open(path).expect("Cannot find test image!");
-            let mut decoder = Decoder::open(img_file).expect("Cannot create decoder");
+            let mut decoder = Decoder::open(img_file)
+                .expect("Cannot create decoder")
+                .with_lenient(true);
 
             decoder.next_image().expect("Cannot read image IFD");
             assert_eq!(decoder.colortype().unwrap(), expected_type);
@@ -825,7 +827,7 @@ fn test_predictor_3_gray_f32() {
 }
 
 #[test]
-#[cfg(feature = "zstd")]
+#[cfg(any(feature = "zstd", feature = "zstd-safe-rust"))]
 fn test_zstd_compression() {
     // gdal_translate -co COMPRESS=ZSTD -co ZSTD_LEVEL=20 int16.tif int16_zstd.tif
     test_image_sum_i16("int16_zstd.tif", ColorType::Gray(16), 354396);
@@ -975,7 +977,7 @@ fn extra_bits_gray() {
 
 #[test]
 fn extra_bits_rgb() {
-    test_image_sum_u8("extra_bits_rgb_8b.tiff", ColorType::RGB(8), 0);
+    test_image_sum_u8("extra_bits_rgb_8b.tiff", ColorType::RGBA(8), 64);
 }
 
 #[test]

tests/predict.rs

@@ -233,3 +233,167 @@ fn test_rgb_u64_predict_roundtrip() {
 fn test_ycbcr_u8_predict_roundtrip() {
     test_u8_predict_roundtrip::<colortype::YCbCr8>("tiled-jpeg-ycbcr.tif", ColorType::YCbCr(8));
 }
+
+// ---------------------------------------------------------------------------
+// Extended bit depths (9-15 promoted to u16, 17-31 promoted to u32).
+//
+// A horizontal-predicted n-bit sample stores its delta in exactly n bits,
+// i.e. modulo 2^n, so reconstruction must also be modulo 2^n. The decoder
+// accumulates in the promoted storage width and reduces back to n bits;
+// these tests pin that reduction down with exact pixel values, including
+// deltas that wrap modulo 2^n. The encoder does not support extended
+// depths, so the TIFFs are hand-built.
+// ---------------------------------------------------------------------------
+
+/// Hand-build a minimal little-endian, single-strip, uncompressed grayscale
+/// TIFF with `Predictor::Horizontal` and the given (possibly non-standard)
+/// bit depth. `pixels` are the intended sample values; they are converted to
+/// horizontal differences modulo `2^bits` and bit-packed MSB-first with each
+/// row padded to a byte boundary — the only representation an n-bit field
+/// can hold.
+fn build_gray_hpredict_tiff(
+    width: u32,
+    height: u32,
+    bits: u8,
+    photometric: u16,
+    pixels: &[u32],
+) -> Vec<u8> {
+    let max = ((1u64 << bits) - 1) as u32;
+    let row_samples = width as usize;
+    assert_eq!(pixels.len(), row_samples * height as usize);
+    assert!(pixels.iter().all(|&v| v <= max));
+
+    // Per-row horizontal differencing modulo 2^bits.
+    let mut deltas = Vec::with_capacity(pixels.len());
+    for row in pixels.chunks(row_samples) {
+        for (i, &v) in row.iter().enumerate() {
+            deltas.push(if i == 0 {
+                v
+            } else {
+                v.wrapping_sub(row[i - 1]) & max
+            });
+        }
+    }
+
+    // Bit-pack MSB-first, each row padded to a byte boundary.
+    let row_bytes = (row_samples * bits as usize).div_ceil(8);
+    let mut data = vec![0u8; row_bytes * height as usize];
+    for (r, row) in deltas.chunks(row_samples).enumerate() {
+        for (i, &d) in row.iter().enumerate() {
+            let start = r * row_bytes * 8 + i * bits as usize;
+            for (off, b) in (start..).zip((0..bits).rev()) {
+                if (d >> b) & 1 == 1 {
+                    data[off / 8] |= 0x80 >> (off % 8);
+                }
+            }
+        }
+    }
+
+    // Classic little-endian TIFF: header, strip data, then a single IFD.
+    let mut out = Vec::new();
+    out.extend_from_slice(b"II");
+    out.extend_from_slice(&42u16.to_le_bytes());
+    let data_offset = 8u32;
+    let ifd_offset = data_offset + data.len() as u32;
+    out.extend_from_slice(&ifd_offset.to_le_bytes());
+    out.extend_from_slice(&data);
+
+    const SHORT: u16 = 3;
+    const LONG: u16 = 4;
+    let entries: &[(u16, u16, u32)] = &[
+        (256, LONG, width),                   // ImageWidth
+        (257, LONG, height),                  // ImageLength
+        (258, SHORT, u32::from(bits)),        // BitsPerSample
+        (259, SHORT, 1),                      // Compression: none
+        (262, SHORT, u32::from(photometric)), // PhotometricInterpretation
+        (273, LONG, data_offset),             // StripOffsets
+        (277, SHORT, 1),                      // SamplesPerPixel
+        (278, LONG, height),                  // RowsPerStrip
+        (279, LONG, data.len() as u32),       // StripByteCounts
+        (317, SHORT, 2),                      // Predictor: horizontal
+        (339, SHORT, 1),                      // SampleFormat: unsigned integer
+    ];
+    out.extend_from_slice(&(entries.len() as u16).to_le_bytes());
+    for &(tag, ty, value) in entries {
+        out.extend_from_slice(&tag.to_le_bytes());
+        out.extend_from_slice(&ty.to_le_bytes());
+        out.extend_from_slice(&1u32.to_le_bytes());
+        // A count-1 SHORT payload occupies the low bytes of the value field.
+        out.extend_from_slice(&value.to_le_bytes());
+    }
+    out.extend_from_slice(&0u32.to_le_bytes()); // no next IFD
+    out
+}
+
+fn decode_gray_u16(tiff: Vec<u8>, bits: u8) -> Vec<u16> {
+    let mut decoder = Decoder::open(Cursor::new(tiff)).expect("Cannot create decoder");
+    decoder.next_image().unwrap();
+    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(bits));
+    match decoder.read_image().unwrap() {
+        DecodingSampleBuffer::U16(res) => res,
+        _ => panic!("Wrong data type"),
+    }
+}
+
+fn decode_gray_u32(tiff: Vec<u8>, bits: u8) -> Vec<u32> {
+    let mut decoder = Decoder::open(Cursor::new(tiff)).expect("Cannot create decoder");
+    decoder.next_image().unwrap();
+    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(bits));
+    match decoder.read_image().unwrap() {
+        DecodingSampleBuffer::U32(res) => res,
+        _ => panic!("Wrong data type"),
+    }
+}
+
+#[test]
+fn test_gray12_hpredict_wraparound_exact() {
+    // Pixel row [4095, 0, 1] encodes as deltas [4095, 1, 1] (mod 2^12).
+    // u16 accumulation yields [4095, 4096, 4097]; reduction modulo 2^12
+    // must restore [4095, 0, 1]. Saturating instead would corrupt the two
+    // wrapped samples to 4095.
+    let tiff = build_gray_hpredict_tiff(3, 1, 12, 1, &[4095, 0, 1]);
+    assert_eq!(decode_gray_u16(tiff, 12), vec![4095, 0, 1]);
+}
+
+#[test]
+fn test_gray12_hpredict_wraparound_white_is_zero_exact() {
+    // Same stored samples with PhotometricInterpretation = WhiteIsZero:
+    // after the mod-2^12 reduction the decoder inverts as (2^12 - 1) - v.
+    let tiff = build_gray_hpredict_tiff(3, 1, 12, 0, &[4095, 0, 1]);
+    assert_eq!(decode_gray_u16(tiff, 12), vec![0, 4095, 4094]);
+}
+
+#[test]
+fn test_gray20_hpredict_wraparound_exact() {
+    // The same wrap-around shape on the u32 storage path (17-31 bits).
+    let tiff = build_gray_hpredict_tiff(3, 1, 20, 1, &[0xF_FFFF, 0, 1]);
+    assert_eq!(decode_gray_u32(tiff, 20), vec![0xF_FFFF, 0, 1]);
+}
+
+#[test]
+fn test_extended_depth_hpredict_random_roundtrip() {
+    // Deterministic pseudo-random pixels across a spread of extended depths;
+    // encode-then-decode must be the identity for every sample, including
+    // every mod-2^n wrap-around the differencing produces. Three rows verify
+    // that prediction restarts per row.
+    let mut state = 0x243F_6A88_85A3_08D3u64;
+    let mut next = move || {
+        state = state
+            .wrapping_mul(6364136223846793005)
+            .wrapping_add(1442695040888963407);
+        (state >> 33) as u32
+    };
+    for &bits in &[9u8, 11, 12, 15] {
+        let max = (1u32 << bits) - 1;
+        let pixels: Vec<u32> = (0..16 * 3).map(|_| next() & max).collect();
+        let tiff = build_gray_hpredict_tiff(16, 3, bits, 1, &pixels);
+        let expected: Vec<u16> = pixels.iter().map(|&v| v as u16).collect();
+        assert_eq!(decode_gray_u16(tiff, bits), expected, "bits={bits}");
+    }
+    for &bits in &[17u8, 20, 25, 31] {
+        let max = ((1u64 << bits) - 1) as u32;
+        let pixels: Vec<u32> = (0..16 * 3).map(|_| next() & max).collect();
+        let tiff = build_gray_hpredict_tiff(16, 3, bits, 1, &pixels);
+        assert_eq!(decode_gray_u32(tiff, bits), pixels, "bits={bits}");
+    }
+}