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Diffstat (limited to 'vendor/exr/src/compression/piz/wavelet.rs')
| -rw-r--r-- | vendor/exr/src/compression/piz/wavelet.rs | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/vendor/exr/src/compression/piz/wavelet.rs b/vendor/exr/src/compression/piz/wavelet.rs new file mode 100644 index 0000000..76f996e --- /dev/null +++ b/vendor/exr/src/compression/piz/wavelet.rs @@ -0,0 +1,422 @@ + +//! Wavelet encoding and decoding. +// see https://github.com/AcademySoftwareFoundation/openexr/blob/8cd1b9210855fa4f6923c1b94df8a86166be19b1/OpenEXR/IlmImf/ImfWav.cpp + +use crate::error::IoResult; +use crate::math::Vec2; + +#[allow(unused)] +#[inline] +pub fn encode(buffer: &mut [u16], count: Vec2<usize>, size: Vec2<usize>, max_value: u16) -> IoResult<()> { + if is_14_bit(max_value) { encode_14_or_16_bit(buffer, count, size, true) } + else { encode_14_or_16_bit(buffer, count, size, false) } +} + +#[allow(unused)] +#[inline] +pub fn encode_14_or_16_bit( + buffer: &mut [u16], + Vec2(count_x, count_y): Vec2<usize>, + Vec2(offset_x, offset_y): Vec2<usize>, + is_14_bit: bool // true if maximum buffer[i] value < (1 << 14) +) -> IoResult<()> +{ + let count = count_x.min(count_y); + let encode = if is_14_bit { encode_14bit } else { encode_16bit }; // assume inlining and constant propagation + + let mut p: usize = 1; // TODO i32? + let mut p2: usize = 2; // TODO what is p?? + + while p2 <= count { + + let mut position_y = 0; + let end_y = 0 + offset_y * (count_y - p2); + let (offset1_x, offset1_y) = (offset_x * p, offset_y * p); + let (offset2_x, offset2_y) = (offset_x * p2, offset_y * p2); + + // y-loop + while position_y <= end_y { // TODO: for py in (index..ey).nth(offset_2.0) + + let mut position_x = position_y; + let end_x = position_x + offset_x * (count_x - p2); + + // x-loop + while position_x <= end_x { + let pos_right = position_x + offset1_x; + let pos_top = position_x + offset1_y; + let pos_top_right = pos_top + offset1_x; + + assert!(position_x < buffer.len()); + assert!(pos_right < buffer.len()); + assert!(pos_top < buffer.len()); + assert!(pos_top_right < buffer.len()); + + if is_14_bit { + debug_assert!(self::is_14_bit(buffer[position_x])); + debug_assert!(self::is_14_bit(buffer[pos_right])); + } + + let (center, right) = encode(buffer[position_x], buffer[pos_right]); + let (top, top_right) = encode(buffer[pos_top], buffer[pos_top_right]); + + let (center, top) = encode(center, top); + let (right, top_right) = encode(right, top_right); + + buffer[position_x] = center; // TODO rustify + buffer[pos_top] = top; + buffer[pos_right] = right; + buffer[pos_top_right] = top_right; + + position_x += offset2_x; + } + + // encode remaining odd pixel column + if count_x & p != 0 { + let pos_top = position_x + offset1_y; + let (center, top) = encode(buffer[position_x], buffer[pos_top]); + + buffer[position_x] = center; + buffer[pos_top] = top; + } + + position_y += offset2_y; + } + + // encode possibly remaining odd row + if count_y & p != 0 { + let mut position_x = position_y; + let end_x = position_y + offset_x * (count_x - p2); + + while position_x <= end_x { + let pos_right = position_x + offset1_x; + let (center, right) = encode(buffer[position_x], buffer[pos_right]); + + buffer[pos_right] = right; + buffer[position_x] = center; + + position_x += offset2_x; + } + } + + p = p2; + p2 <<= 1; + } + + Ok(()) +} + +#[inline] +pub fn decode(buffer: &mut [u16], count: Vec2<usize>, size: Vec2<usize>, max_value: u16) -> IoResult<()> { + if is_14_bit(max_value) { decode_14_or_16_bit(buffer, count, size, true) } + else { decode_14_or_16_bit(buffer, count, size, false) } +} + +#[inline] +pub fn decode_14_or_16_bit( + buffer: &mut [u16], + Vec2(count_x, count_y): Vec2<usize>, + Vec2(offset_x, offset_y): Vec2<usize>, + is_14_bit: bool // true if maximum buffer[i] value < (1 << 14) +) -> IoResult<()> +{ + let count = count_x.min(count_y); + let decode = if is_14_bit { decode_14bit } else { decode_16bit }; // assume inlining and constant propagation + + let mut p: usize = 1; // TODO i32? + let mut p2: usize; // TODO i32? + + // search max level + while p <= count { + p <<= 1; + } + + p >>= 1; + p2 = p; + p >>= 1; + + while p >= 1 { + + let mut position_y = 0; + let end_y = 0 + offset_y * (count_y - p2); + + let (offset1_x, offset1_y) = (offset_x * p, offset_y * p); + let (offset2_x, offset2_y) = (offset_x * p2, offset_y * p2); + + debug_assert_ne!(offset_x, 0, "offset should not be zero"); + debug_assert_ne!(offset_y, 0, "offset should not be zero"); + + while position_y <= end_y { + let mut position_x = position_y; + let end_x = position_x + offset_x * (count_x - p2); + + while position_x <= end_x { + let pos_right = position_x + offset1_x; + let pos_top = position_x + offset1_y; + let pos_top_right = pos_top + offset1_x; + + assert!(position_x < buffer.len()); + assert!(pos_right < buffer.len()); + assert!(pos_top < buffer.len()); + assert!(pos_top_right < buffer.len()); + + let (center, top) = decode(buffer[position_x], buffer[pos_top]); + let (right, top_right) = decode(buffer[pos_right], buffer[pos_top_right]); + + let (center, right) = decode(center, right); + let (top, top_right) = decode(top, top_right); + + buffer[position_x] = center; // TODO rustify + buffer[pos_top] = top; + buffer[pos_right] = right; + buffer[pos_top_right] = top_right; + + position_x += offset2_x; + } + + // decode last odd remaining x value + if count_x & p != 0 { + let pos_top = position_x + offset1_y; + let (center, top) = decode(buffer[position_x], buffer[pos_top]); + + buffer[position_x] = center; + buffer[pos_top] = top; + } + + position_y += offset2_y; + } + + // decode remaining odd row + if count_y & p != 0 { + let mut position_x = position_y; + let end_x = position_x + offset_x * (count_x - p2); + + while position_x <= end_x { + let pos_right = position_x + offset1_x; + let (center, right) = decode(buffer[position_x], buffer[pos_right]); + + buffer[position_x] = center; + buffer[pos_right] = right; + + position_x += offset2_x; + } + } + + p2 = p; + p >>= 1; + } + + Ok(()) +} + +#[inline] +fn is_14_bit(value: u16) -> bool { + value < (1 << 14) +} + +/// Untransformed data values should be less than (1 << 14). +#[inline] +#[allow(unused)] +fn encode_14bit(a: u16, b: u16) -> (u16, u16) { + let (a, b) = (a as i16, b as i16); + + let m = (a + b) >> 1; + let d = a - b; + + (m as u16, d as u16) // TODO explicitly wrap? +} + +#[inline] +#[allow(unused)] +fn decode_14bit(l: u16, h: u16) -> (u16, u16) { + let (l, h) = (l as i16, h as i16); + + let hi = h as i32; + let ai = l as i32 + (hi & 1) + (hi >> 1); + + let a = ai as i16; // TODO explicitly wrap? + let b = (ai - hi) as i16; // TODO explicitly wrap? + + (a as u16, b as u16) // TODO explicitly wrap? +} + + +const BIT_COUNT: i32 = 16; +const OFFSET: i32 = 1 << (BIT_COUNT - 1); +const MOD_MASK: i32 = (1 << BIT_COUNT) - 1; + +#[inline] +fn encode_16bit(a: u16, b: u16) -> (u16, u16) { + let (a, b) = (a as i32, b as i32); + + let a_offset = (a + OFFSET) & MOD_MASK; + let mut m = (a_offset + b) >> 1; + let d = a_offset - b; + + if d < 0 { m = (m + OFFSET) & MOD_MASK; } + let d = d & MOD_MASK; + + (m as u16, d as u16) // TODO explicitly wrap? +} + +#[inline] +fn decode_16bit(l: u16, h: u16) -> (u16, u16) { + let (m, d) = (l as i32, h as i32); + + let b = (m - (d >> 1)) & MOD_MASK; + let a = (d + b - OFFSET) & MOD_MASK; + + (a as u16, b as u16) // TODO explicitly wrap? +} + + + +#[cfg(test)] +mod test { + use crate::math::Vec2; + use crate::compression::piz::wavelet::is_14_bit; + + #[test] + fn roundtrip_14_bit_values(){ + let data = [ + (13, 54), (3, 123), (423, 53), (1, 23), (23, 515), (513, 43), + (16374, 16381), (16284, 3), (2, 1), (0, 0), (0, 4), (3, 0) + ]; + + for &values in &data { + let (l, h) = super::encode_14bit(values.0, values.1); + let result = super::decode_14bit(l, h); + assert_eq!(values, result); + } + } + + #[test] + fn roundtrip_16_bit_values(){ + let data = [ + (13, 54), (3, 123), (423, 53), (1, 23), (23, 515), (513, 43), + (16385, 56384), (18384, 36384), (2, 1), (0, 0), (0, 4), (3, 0) + ]; + + for &values in &data { + let (l, h) = super::encode_16bit(values.0, values.1); + let result = super::decode_16bit(l, h); + assert_eq!(values, result); + } + } + + #[test] + fn roundtrip_14bit_image(){ + let data: [u16; 6 * 4] = [ + 13, 54, 3, 123, 423, 53, + 1, 23, 23, 515, 513, 43, + 16374, 16381, 16284, 3, 2, 1, + 0, 0, 0, 4, 3, 0, + ]; + + let max = *data.iter().max().unwrap(); + debug_assert!(is_14_bit(max)); + + let mut transformed = data.clone(); + + super::encode(&mut transformed, Vec2(6, 4), Vec2(1,6), max).unwrap(); + super::decode(&mut transformed, Vec2(6, 4), Vec2(1,6), max).unwrap(); + + assert_eq!(data, transformed); + } + + #[test] + fn roundtrip_16bit_image(){ + let data: [u16; 6 * 4] = [ + 13, 54, 3, 123, 423, 53, + 1, 23, 23, 515, 513, 43, + 16385, 56384, 18384, 36384, 2, 1, + 0, 0, 0, 4, 3, 0, + ]; + + let max = *data.iter().max().unwrap(); + debug_assert!(!is_14_bit(max)); + + let mut transformed = data.clone(); + + super::encode(&mut transformed, Vec2(6, 4), Vec2(1,6), max).unwrap(); + super::decode(&mut transformed, Vec2(6, 4), Vec2(1,6), max).unwrap(); + + assert_eq!(data, transformed); + } + + /// inspired by https://github.com/AcademySoftwareFoundation/openexr/blob/master/OpenEXR/IlmImfTest/testWav.cpp + #[test] + fn ground_truth(){ + test_size(1, 1); + test_size(2, 2); + test_size(32, 32); + test_size(1024, 16); + test_size(16, 1024); + test_size(997, 37); + test_size(37, 997); + test_size(1024, 1024); + test_size(997, 997); + + fn test_size(x: usize, y: usize) { + let xy = Vec2(x, y); + roundtrip(noise_14bit(xy), xy); + roundtrip(noise_16bit(xy), xy); + roundtrip(solid(xy, 0), xy); + roundtrip(solid(xy, 1), xy); + roundtrip(solid(xy, 0xffff), xy); + roundtrip(solid(xy, 0x3fff), xy); + roundtrip(solid(xy, 0x3ffe), xy); + roundtrip(solid(xy, 0x3fff), xy); + roundtrip(solid(xy, 0xfffe), xy); + roundtrip(solid(xy, 0xffff), xy); + roundtrip(verticals(xy, 0xffff), xy); + roundtrip(verticals(xy, 0x3fff), xy); + roundtrip(horizontals(xy, 0xffff), xy); + roundtrip(horizontals(xy, 0x3fff), xy); + roundtrip(diagonals(xy, 0xffff), xy); + roundtrip(diagonals(xy, 0x3fff), xy); + } + + fn roundtrip(data: Vec<u16>, size: Vec2<usize>){ + assert_eq!(data.len(), size.area()); + + let max = *data.iter().max().unwrap(); + let offset = Vec2(1, size.0); + + let mut transformed = data.clone(); + super::encode(&mut transformed, size, offset, max).unwrap(); + super::decode(&mut transformed, size, offset, max).unwrap(); + + assert_eq!(data, transformed); + } + + fn noise_14bit(size: Vec2<usize>) -> Vec<u16> { + (0..size.area()).map(|_| (rand::random::<i32>() & 0x3fff) as u16).collect() + } + + fn noise_16bit(size: Vec2<usize>) -> Vec<u16> { + (0..size.area()).map(|_| rand::random::<u16>()).collect() + } + + fn solid(size: Vec2<usize>, value: u16) -> Vec<u16> { + vec![value; size.area()] + } + + fn verticals(size: Vec2<usize>, max_value: u16) -> Vec<u16> { + std::iter::repeat_with(|| (0 .. size.0).map(|x| if x & 1 != 0 { 0 } else { max_value })) + .take(size.1).flatten().collect() + } + + fn horizontals(size: Vec2<usize>, max_value: u16) -> Vec<u16> { + (0 .. size.1) + .flat_map(|y| std::iter::repeat(if y & 1 != 0 { 0 } else { max_value }).take(size.0)) + .collect() + } + + fn diagonals(size: Vec2<usize>, max_value: u16) -> Vec<u16> { + (0 .. size.1).flat_map(|y| { + (0 .. size.0).map(move |x| if (x + y) & 1 != 0 { 0 } else { max_value }) + }).collect() + } + + } +}
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