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Diffstat (limited to 'vendor/image/src/codecs/webp/lossless_transform.rs')
| -rw-r--r-- | vendor/image/src/codecs/webp/lossless_transform.rs | 464 |
1 files changed, 0 insertions, 464 deletions
diff --git a/vendor/image/src/codecs/webp/lossless_transform.rs b/vendor/image/src/codecs/webp/lossless_transform.rs deleted file mode 100644 index f9a82c1..0000000 --- a/vendor/image/src/codecs/webp/lossless_transform.rs +++ /dev/null @@ -1,464 +0,0 @@ -use std::convert::TryFrom; -use std::convert::TryInto; - -use super::lossless::subsample_size; -use super::lossless::DecoderError; - -#[derive(Debug, Clone)] -pub(crate) enum TransformType { - PredictorTransform { - size_bits: u8, - predictor_data: Vec<u32>, - }, - ColorTransform { - size_bits: u8, - transform_data: Vec<u32>, - }, - SubtractGreen, - ColorIndexingTransform { - table_size: u16, - table_data: Vec<u32>, - }, -} - -impl TransformType { - /// Applies a transform to the image data - pub(crate) fn apply_transform( - &self, - image_data: &mut Vec<u32>, - width: u16, - height: u16, - ) -> Result<(), DecoderError> { - match self { - TransformType::PredictorTransform { - size_bits, - predictor_data, - } => { - let block_xsize = usize::from(subsample_size(width, *size_bits)); - let width = usize::from(width); - let height = usize::from(height); - - if image_data.len() < width * height { - return Err(DecoderError::TransformError); - } - - //handle top and left borders specially - //this involves ignoring mode and just setting prediction values like this - image_data[0] = add_pixels(image_data[0], 0xff000000); - - for x in 1..width { - image_data[x] = add_pixels(image_data[x], get_left(image_data, x, 0, width)); - } - - for y in 1..height { - image_data[y * width] = - add_pixels(image_data[y * width], get_top(image_data, 0, y, width)); - } - - for y in 1..height { - for x in 1..width { - let block_index = (y >> size_bits) * block_xsize + (x >> size_bits); - - let index = y * width + x; - - let green = (predictor_data[block_index] >> 8) & 0xff; - - match green { - 0 => image_data[index] = add_pixels(image_data[index], 0xff000000), - 1 => { - image_data[index] = - add_pixels(image_data[index], get_left(image_data, x, y, width)) - } - 2 => { - image_data[index] = - add_pixels(image_data[index], get_top(image_data, x, y, width)) - } - 3 => { - image_data[index] = add_pixels( - image_data[index], - get_top_right(image_data, x, y, width), - ) - } - 4 => { - image_data[index] = add_pixels( - image_data[index], - get_top_left(image_data, x, y, width), - ) - } - 5 => { - image_data[index] = add_pixels(image_data[index], { - let first = average2( - get_left(image_data, x, y, width), - get_top_right(image_data, x, y, width), - ); - average2(first, get_top(image_data, x, y, width)) - }) - } - 6 => { - image_data[index] = add_pixels( - image_data[index], - average2( - get_left(image_data, x, y, width), - get_top_left(image_data, x, y, width), - ), - ) - } - 7 => { - image_data[index] = add_pixels( - image_data[index], - average2( - get_left(image_data, x, y, width), - get_top(image_data, x, y, width), - ), - ) - } - 8 => { - image_data[index] = add_pixels( - image_data[index], - average2( - get_top_left(image_data, x, y, width), - get_top(image_data, x, y, width), - ), - ) - } - 9 => { - image_data[index] = add_pixels( - image_data[index], - average2( - get_top(image_data, x, y, width), - get_top_right(image_data, x, y, width), - ), - ) - } - 10 => { - image_data[index] = add_pixels(image_data[index], { - let first = average2( - get_left(image_data, x, y, width), - get_top_left(image_data, x, y, width), - ); - let second = average2( - get_top(image_data, x, y, width), - get_top_right(image_data, x, y, width), - ); - average2(first, second) - }) - } - 11 => { - image_data[index] = add_pixels( - image_data[index], - select( - get_left(image_data, x, y, width), - get_top(image_data, x, y, width), - get_top_left(image_data, x, y, width), - ), - ) - } - 12 => { - image_data[index] = add_pixels( - image_data[index], - clamp_add_subtract_full( - get_left(image_data, x, y, width), - get_top(image_data, x, y, width), - get_top_left(image_data, x, y, width), - ), - ) - } - 13 => { - image_data[index] = add_pixels(image_data[index], { - let first = average2( - get_left(image_data, x, y, width), - get_top(image_data, x, y, width), - ); - clamp_add_subtract_half( - first, - get_top_left(image_data, x, y, width), - ) - }) - } - _ => {} - } - } - } - } - TransformType::ColorTransform { - size_bits, - transform_data, - } => { - let block_xsize = usize::from(subsample_size(width, *size_bits)); - let width = usize::from(width); - let height = usize::from(height); - - for y in 0..height { - for x in 0..width { - let block_index = (y >> size_bits) * block_xsize + (x >> size_bits); - - let index = y * width + x; - - let multiplier = - ColorTransformElement::from_color_code(transform_data[block_index]); - - image_data[index] = transform_color(&multiplier, image_data[index]); - } - } - } - TransformType::SubtractGreen => { - let width = usize::from(width); - for y in 0..usize::from(height) { - for x in 0..width { - image_data[y * width + x] = add_green(image_data[y * width + x]); - } - } - } - TransformType::ColorIndexingTransform { - table_size, - table_data, - } => { - let mut new_image_data = - Vec::with_capacity(usize::from(width) * usize::from(height)); - - let table_size = *table_size; - let width_bits: u8 = if table_size <= 2 { - 3 - } else if table_size <= 4 { - 2 - } else if table_size <= 16 { - 1 - } else { - 0 - }; - - let bits_per_pixel = 8 >> width_bits; - let mask = (1 << bits_per_pixel) - 1; - - let mut src = 0; - let width = usize::from(width); - - let pixels_per_byte = 1 << width_bits; - let count_mask = pixels_per_byte - 1; - let mut packed_pixels = 0; - - for _y in 0..usize::from(height) { - for x in 0..width { - if (x & count_mask) == 0 { - packed_pixels = (image_data[src] >> 8) & 0xff; - src += 1; - } - - let pixels: usize = (packed_pixels & mask).try_into().unwrap(); - let new_val = if pixels >= table_size.into() { - 0x00000000 - } else { - table_data[pixels] - }; - - new_image_data.push(new_val); - - packed_pixels >>= bits_per_pixel; - } - } - - *image_data = new_image_data; - } - } - - Ok(()) - } -} - -//predictor functions - -/// Adds 2 pixels mod 256 for each pixel -pub(crate) fn add_pixels(a: u32, b: u32) -> u32 { - let new_alpha = ((a >> 24) + (b >> 24)) & 0xff; - let new_red = (((a >> 16) & 0xff) + ((b >> 16) & 0xff)) & 0xff; - let new_green = (((a >> 8) & 0xff) + ((b >> 8) & 0xff)) & 0xff; - let new_blue = ((a & 0xff) + (b & 0xff)) & 0xff; - - (new_alpha << 24) + (new_red << 16) + (new_green << 8) + new_blue -} - -/// Get left pixel -fn get_left(data: &[u32], x: usize, y: usize, width: usize) -> u32 { - data[y * width + x - 1] -} - -/// Get top pixel -fn get_top(data: &[u32], x: usize, y: usize, width: usize) -> u32 { - data[(y - 1) * width + x] -} - -/// Get pixel to top right -fn get_top_right(data: &[u32], x: usize, y: usize, width: usize) -> u32 { - // if x == width - 1 this gets the left most pixel of the current row - // as described in the specification - data[(y - 1) * width + x + 1] -} - -/// Get pixel to top left -fn get_top_left(data: &[u32], x: usize, y: usize, width: usize) -> u32 { - data[(y - 1) * width + x - 1] -} - -/// Get average of 2 pixels -fn average2(a: u32, b: u32) -> u32 { - let mut avg = 0u32; - for i in 0..4 { - let sub_a: u8 = ((a >> (i * 8)) & 0xff).try_into().unwrap(); - let sub_b: u8 = ((b >> (i * 8)) & 0xff).try_into().unwrap(); - avg |= u32::from(sub_average2(sub_a, sub_b)) << (i * 8); - } - avg -} - -/// Get average of 2 bytes -fn sub_average2(a: u8, b: u8) -> u8 { - ((u16::from(a) + u16::from(b)) / 2).try_into().unwrap() -} - -/// Get a specific byte from argb pixel -fn get_byte(val: u32, byte: u8) -> u8 { - ((val >> (byte * 8)) & 0xff).try_into().unwrap() -} - -/// Get byte as i32 for convenience -fn get_byte_i32(val: u32, byte: u8) -> i32 { - i32::from(get_byte(val, byte)) -} - -/// Select left or top byte -fn select(left: u32, top: u32, top_left: u32) -> u32 { - let predict_alpha = get_byte_i32(left, 3) + get_byte_i32(top, 3) - get_byte_i32(top_left, 3); - let predict_red = get_byte_i32(left, 2) + get_byte_i32(top, 2) - get_byte_i32(top_left, 2); - let predict_green = get_byte_i32(left, 1) + get_byte_i32(top, 1) - get_byte_i32(top_left, 1); - let predict_blue = get_byte_i32(left, 0) + get_byte_i32(top, 0) - get_byte_i32(top_left, 0); - - let predict_left = i32::abs(predict_alpha - get_byte_i32(left, 3)) - + i32::abs(predict_red - get_byte_i32(left, 2)) - + i32::abs(predict_green - get_byte_i32(left, 1)) - + i32::abs(predict_blue - get_byte_i32(left, 0)); - let predict_top = i32::abs(predict_alpha - get_byte_i32(top, 3)) - + i32::abs(predict_red - get_byte_i32(top, 2)) - + i32::abs(predict_green - get_byte_i32(top, 1)) - + i32::abs(predict_blue - get_byte_i32(top, 0)); - - if predict_left < predict_top { - left - } else { - top - } -} - -/// Clamp a to [0, 255] -fn clamp(a: i32) -> i32 { - if a < 0 { - 0 - } else if a > 255 { - 255 - } else { - a - } -} - -/// Clamp add subtract full on one part -fn clamp_add_subtract_full_sub(a: i32, b: i32, c: i32) -> i32 { - clamp(a + b - c) -} - -/// Clamp add subtract half on one part -fn clamp_add_subtract_half_sub(a: i32, b: i32) -> i32 { - clamp(a + (a - b) / 2) -} - -/// Clamp add subtract full on 3 pixels -fn clamp_add_subtract_full(a: u32, b: u32, c: u32) -> u32 { - let mut value: u32 = 0; - for i in 0..4u8 { - let sub_a: i32 = ((a >> (i * 8)) & 0xff).try_into().unwrap(); - let sub_b: i32 = ((b >> (i * 8)) & 0xff).try_into().unwrap(); - let sub_c: i32 = ((c >> (i * 8)) & 0xff).try_into().unwrap(); - value |= - u32::try_from(clamp_add_subtract_full_sub(sub_a, sub_b, sub_c)).unwrap() << (i * 8); - } - value -} - -/// Clamp add subtract half on 2 pixels -fn clamp_add_subtract_half(a: u32, b: u32) -> u32 { - let mut value = 0; - for i in 0..4u8 { - let sub_a: i32 = ((a >> (i * 8)) & 0xff).try_into().unwrap(); - let sub_b: i32 = ((b >> (i * 8)) & 0xff).try_into().unwrap(); - value |= u32::try_from(clamp_add_subtract_half_sub(sub_a, sub_b)).unwrap() << (i * 8); - } - - value -} - -//color transform - -#[derive(Debug, Clone, Copy)] -struct ColorTransformElement { - green_to_red: u8, - green_to_blue: u8, - red_to_blue: u8, -} - -impl ColorTransformElement { - fn from_color_code(color_code: u32) -> ColorTransformElement { - ColorTransformElement { - green_to_red: (color_code & 0xff).try_into().unwrap(), - green_to_blue: ((color_code >> 8) & 0xff).try_into().unwrap(), - red_to_blue: ((color_code >> 16) & 0xff).try_into().unwrap(), - } - } -} - -/// Does color transform on red and blue transformed by green -fn color_transform(red: u8, blue: u8, green: u8, trans: &ColorTransformElement) -> (u8, u8) { - let mut temp_red = u32::from(red); - let mut temp_blue = u32::from(blue); - - //as does the conversion from u8 to signed two's complement i8 required - temp_red += color_transform_delta(trans.green_to_red as i8, green as i8); - temp_blue += color_transform_delta(trans.green_to_blue as i8, green as i8); - temp_blue += color_transform_delta(trans.red_to_blue as i8, temp_red as i8); - - ( - (temp_red & 0xff).try_into().unwrap(), - (temp_blue & 0xff).try_into().unwrap(), - ) -} - -/// Does color transform on 2 numbers -fn color_transform_delta(t: i8, c: i8) -> u32 { - ((i16::from(t) * i16::from(c)) as u32) >> 5 -} - -// Does color transform on a pixel with a color transform element -fn transform_color(multiplier: &ColorTransformElement, color_value: u32) -> u32 { - let alpha = get_byte(color_value, 3); - let red = get_byte(color_value, 2); - let green = get_byte(color_value, 1); - let blue = get_byte(color_value, 0); - - let (new_red, new_blue) = color_transform(red, blue, green, multiplier); - - (u32::from(alpha) << 24) - + (u32::from(new_red) << 16) - + (u32::from(green) << 8) - + u32::from(new_blue) -} - -//subtract green function - -/// Adds green to red and blue of a pixel -fn add_green(argb: u32) -> u32 { - let red = (argb >> 16) & 0xff; - let green = (argb >> 8) & 0xff; - let blue = argb & 0xff; - - let new_red = (red + green) & 0xff; - let new_blue = (blue + green) & 0xff; - - (argb & 0xff00ff00) | (new_red << 16) | (new_blue) -} |