Implement block out area (#18)

Add `-b, --block-out` CLI option

benches/benchmark.rs

@@ -20,6 +20,7 @@ fn criterion_benchmark(c: &mut Criterion) {
         do_not_check_dimensions: true,
         detect_anti_aliased_pixels: false,
         blend_factor_of_unchanged_pixels: None,
+        block_out_areas: None,
     };
 
     c.bench_function("1000 × 667 pixels", |b| {

src/cli.rs

@@ -1,6 +1,7 @@
 use anyhow::{anyhow, Context, Result};
 use colored::*;
 use getopts::{Matches, Options};
+use std::collections::HashSet;
 use std::env;
 
 const VERSION: Option<&'static str> = option_env!("CARGO_PKG_VERSION");
@@ -12,6 +13,7 @@ const SHORT_NAME_OUTPUT_IMAGE_PATH: &str = "o";
 const SHORT_NAME_THRESHOLD: &str = "t";
 const SHORT_NAME_DETECT_ANTI_ALIASED_PIXELS: &str = "d";
 const SHORT_NAME_BLEND_FACTOR_OF_UNCHENGED_PIXELS: &str = "a";
+const SHORT_NAME_BLOCK_OUT_AREA: &str = "b";
 const DEFAULT_PATH_OF_DIFF_IMAGE: &str = "diff.png";
 
 pub enum OutputImageBase {
@@ -31,46 +33,53 @@ impl Cli {
 
         let mut options = Options::new();
 
-        options.optflag(SHORT_NAME_HELP, "help", "print this help menu");
-        options.optflag(SHORT_NAME_VERSION, "version", "print the version");
+        options.optflag(SHORT_NAME_HELP, "help", "Print this help menu.");
+        options.optflag(SHORT_NAME_VERSION, "version", "Print the version.");
+
+        options.optmulti(
+            SHORT_NAME_BLOCK_OUT_AREA,
+            "block-out",
+            "Block-out area. Can be repeated multiple times.",
+            "x,y,w,h",
+        );
 
         options.optflag(
             SHORT_NAME_DONT_CHECK_DIMENSIONS,
             "ignore-dimensions",
-            "don't check image dimensions",
+            "Do not check image dimensions.",
         );
 
         options.optflagopt(
             SHORT_NAME_BLEND_FACTOR_OF_UNCHENGED_PIXELS,
             "alpha",
-            "blending factor of unchanged pixels in the diff output. ranges from 0 for pure white to 1 for original brightness. (default: 0.1)",
+            "Blending factor of unchanged pixels in the diff output. Ranges from 0 for pure white to 1 for original brightness. (default: 0.1)",
             "NUM"
         );
 
         options.optflagopt(
             SHORT_NAME_COPY_IMAGE_AS_BASE,
             "copy-image",
-            "copies specific image to output as base. (default: left)",
+            "Copies specific image to output as base. (default: left)",
             "{left, right}",
         );
 
         options.optflag(
             SHORT_NAME_DETECT_ANTI_ALIASED_PIXELS,
             "detect-anti-aliased",
-            "detect anti-aliased pixels. (default: false)",
+            "Detects anti-aliased pixels. (default: false)",
         );
 
         options.optopt(
             SHORT_NAME_OUTPUT_IMAGE_PATH,
             "output",
-            "the file path of diff image, PNG only. (default: diff.png)",
+            "The file path of diff image, PNG only. (default: diff.png)",
             "OUTPUT",
         );
 
         options.optopt(
             SHORT_NAME_THRESHOLD,
             "threshold",
-            "matching threshold, ranges from 0 to 1, less more precise. (default: 0.1)",
+            "Matching threshold, ranges from 0 to 1, less more precise. (default: 0.1)",
             "NUM",
         );
 
@@ -198,6 +207,40 @@ impl Cli {
             .get(1)
             .with_context(|| format!("the {} argument is missing", "RIGHT".magenta()).red())?;
 
-        Ok((&left_image, &right_image))
+        Ok((left_image, right_image))
+    }
+
+    pub fn get_block_out_area(&self) -> Option<HashSet<(u32, u32)>> {
+        self.matches
+            .opt_strs(SHORT_NAME_BLOCK_OUT_AREA)
+            .iter()
+            .fold(None, |acc, area| {
+                let area = {
+                    let mut segments = area
+                        .splitn(4, ',')
+                        .map(|segment| segment.parse::<u32>().ok().unwrap_or(0));
+                    let x = segments.next().unwrap_or(0);
+                    let y = segments.next().unwrap_or(0);
+                    let width = segments.next().unwrap_or(0);
+                    let height = segments.next().unwrap_or(0);
+
+                    match (x, y, width, height) {
+                        (0, _, _, _) | (_, 0, _, _) | (_, _, 0, _) | (_, _, _, 0) => None,
+                        (x, y, width, height) => Some((x, y, width, height)),
+                    }
+                };
+                match area {
+                    None => acc,
+                    Some((x, y, width, height)) => {
+                        let mut acc = acc.unwrap_or_default();
+                        for i in x..=x + width {
+                            for j in y..=y + height {
+                                acc.insert((i, j));
+                            }
+                        }
+                        Some(acc)
+                    }
+                }
+            })
     }
 }

src/diff.rs

@@ -1,8 +1,9 @@
-use super::{antialiased, cli, yiq::YIQ};
+use super::{antialiased, cli, yiq::Yiq};
 use anyhow::{anyhow, Context, Result};
 use colored::*;
 use image::io::Reader as ImageIoReader;
 use image::{GenericImageView, ImageBuffer, ImageFormat, Pixel, Rgba, RgbaImage};
+use std::collections::HashSet;
 
 const MAX_YIQ_POSSIBLE_DELTA: f32 = 35215.0;
 const RED_PIXEL: Rgba<u8> = Rgba([255, 0, 0, 255]);
@@ -15,6 +16,7 @@ pub enum DiffResult {
     Different(u32, u32),
     OutOfBounds(u32, u32),
     AntiAliased(u32, u32),
+    BlockedOut(u32, u32),
 }
 
 pub struct RunParams<'a> {
@@ -26,6 +28,7 @@ pub struct RunParams<'a> {
     pub do_not_check_dimensions: bool,
     pub detect_anti_aliased_pixels: bool,
     pub blend_factor_of_unchanged_pixels: Option<f32>,
+    pub block_out_areas: Option<HashSet<(u32, u32)>>,
 }
 
 fn open_and_decode_image(path: &str, which: &str) -> Result<RgbaImage> {
@@ -39,12 +42,13 @@ fn open_and_decode_image(path: &str, which: &str) -> Result<RgbaImage> {
 }
 
 pub fn get_results(
-    left_image: &RgbaImage,
-    right_image: &RgbaImage,
+    left_image: RgbaImage,
+    right_image: RgbaImage,
     threshold: f32,
     detect_anti_aliased_pixels: bool,
     blend_factor_of_unchanged_pixels: Option<f32>,
     output_image_base: &Option<cli::OutputImageBase>,
+    block_out_areas: &Option<HashSet<(u32, u32)>>,
 ) -> Option<(i32, RgbaImage)> {
     let (width, height) = left_image.dimensions();
 
@@ -54,9 +58,15 @@ pub fn get_results(
 
             if left_pixel == right_pixel {
                 DiffResult::Identical(x, y)
+            } else if block_out_areas
+                .as_ref()
+                .and_then(|set| set.contains(&(x, y)).then(|| ()))
+                .is_some()
+            {
+                DiffResult::BlockedOut(x, y)
             } else {
-                let left_pixel = YIQ::from_rgba(left_pixel);
-                let right_pixel = YIQ::from_rgba(right_pixel);
+                let left_pixel = Yiq::from_rgba(left_pixel);
+                let right_pixel = Yiq::from_rgba(right_pixel);
                 let delta = left_pixel.squared_distance(&right_pixel);
 
                 if delta.abs() > threshold {
@@ -90,7 +100,7 @@ pub fn get_results(
             DiffResult::Identical(x, y) | DiffResult::BelowThreshold(x, y) => {
                 if let Some(alpha) = blend_factor_of_unchanged_pixels {
                     let left_pixel = left_image.get_pixel(x, y);
-                    let yiq_y = YIQ::rgb2y(&left_pixel.to_rgb());
+                    let yiq_y = Yiq::rgb2y(&left_pixel.to_rgb());
                     let rgba_a = left_pixel.channels()[3] as f32;
                     let color =
                         super::blend_semi_transparent_white(yiq_y, alpha * rgba_a / 255.0) as u8;
@@ -105,6 +115,7 @@ pub fn get_results(
             DiffResult::AntiAliased(x, y) => {
                 output_image.put_pixel(x, y, YELLOW_PIXEL);
             }
+            DiffResult::BlockedOut(_x, _y) => (),
         }
     }
 
@@ -137,12 +148,13 @@ pub fn run(params: &RunParams) -> Result<Option<i32>> {
     let threshold = MAX_YIQ_POSSIBLE_DELTA * params.threshold * params.threshold;
 
     match get_results(
-        &left_image,
-        &right_image,
+        left_image,
+        right_image,
         threshold,
         params.detect_anti_aliased_pixels,
         params.blend_factor_of_unchanged_pixels,
         &params.output_image_base,
+        &params.block_out_areas,
     ) {
         Some((diffs, output_image)) => {
             output_image
@@ -169,30 +181,33 @@ mod tests {
         do_not_check_dimensions: true,
         detect_anti_aliased_pixels: false,
         blend_factor_of_unchanged_pixels: None,
+        block_out_areas: None,
     };
 
     #[test]
     fn test_zero_width_height() {
         let actual = get_results(
-            &RgbaImage::new(0, 0),
-            &RgbaImage::new(0, 0),
+            RgbaImage::new(0, 0),
+            RgbaImage::new(0, 0),
             RUN_PARAMS.threshold,
             RUN_PARAMS.detect_anti_aliased_pixels,
             RUN_PARAMS.blend_factor_of_unchanged_pixels,
             &RUN_PARAMS.output_image_base,
+            &RUN_PARAMS.block_out_areas,
         );
         assert_eq!(None, actual);
     }
 
     #[test]
     fn test_1_pixel() {
         let actual = get_results(
-            &RgbaImage::new(1, 1),
-            &RgbaImage::new(1, 1),
+            RgbaImage::new(1, 1),
+            RgbaImage::new(1, 1),
             RUN_PARAMS.threshold,
             RUN_PARAMS.detect_anti_aliased_pixels,
             RUN_PARAMS.blend_factor_of_unchanged_pixels,
             &RUN_PARAMS.output_image_base,
+            &RUN_PARAMS.block_out_areas,
         );
         assert_eq!(None, actual);
     }
@@ -202,12 +217,13 @@ mod tests {
         let mut left = RgbaImage::new(1, 1);
         left.put_pixel(0, 0, YELLOW_PIXEL);
         let actual = get_results(
-            &left,
-            &RgbaImage::new(1, 1),
+            left,
+            RgbaImage::new(1, 1),
             RUN_PARAMS.threshold,
             RUN_PARAMS.detect_anti_aliased_pixels,
             RUN_PARAMS.blend_factor_of_unchanged_pixels,
             &RUN_PARAMS.output_image_base,
+            &RUN_PARAMS.block_out_areas,
         );
 
         let mut expected_image = RgbaImage::new(1, 1);

src/lib.rs

@@ -2,9 +2,9 @@ pub mod cli;
 pub mod diff;
 mod yiq;
 
+use crate::yiq::Yiq;
 use image::{Pixel, RgbaImage};
 use std::cmp;
-use yiq::*;
 
 fn get_diagonal_neighbours(x1: u32, y1: u32, width: u32, height: u32) -> ((u32, u32), (u32, u32)) {
     // (x0, y0)
@@ -88,7 +88,7 @@ pub fn antialiased(
             }
 
             let neighbor = left.get_pixel(x, y).to_rgb();
-            let delta = YIQ::delta_y(center, &neighbor);
+            let delta = Yiq::delta_y(center, &neighbor);
 
             if delta == 0.0 {
                 zeros += 1;

src/main.rs

@@ -21,6 +21,7 @@ fn main() -> Result<()> {
     let threshold = cli.get_threshold()?;
     let detect_anti_aliased_pixels = cli.detect_anti_aliased_pixels();
     let blend_factor_of_unchanged_pixels = cli.blend_factor_of_unchanged_pixels()?;
+    let block_out_areas = cli.get_block_out_area();
 
     diff::run(&diff::RunParams {
         left,
@@ -31,6 +32,7 @@ fn main() -> Result<()> {
         do_not_check_dimensions,
         detect_anti_aliased_pixels,
         blend_factor_of_unchanged_pixels,
+        block_out_areas,
     })
     .map(|code| {
         if let Some(code) = code {

src/yiq.rs

@@ -1,13 +1,13 @@
 use image::Pixel;
 
 #[derive(Debug, PartialEq)]
-pub struct YIQ {
+pub struct Yiq {
     y: f32, // luminance, in range [0, 1]
     i: f32, // hue of color, in range ~ [-0.5, 0.5]
     q: f32, // saturation of color, in range ~ [-0.5, 0.5]
 }
 
-impl YIQ {
+impl Yiq {
     #[allow(clippy::many_single_char_names, clippy::excessive_precision)]
     pub fn rgb2y(rgb: &image::Rgb<u8>) -> f32 {
         let rgb = rgb.channels();
@@ -68,27 +68,27 @@ impl YIQ {
 
 #[cfg(test)]
 mod tests {
-    use super::YIQ;
+    use super::Yiq;
 
     #[test]
     fn test_from_rgb() {
-        let expected = YIQ {
+        let expected = Yiq {
             y: 0.0,
             i: 0.0,
             q: 0.0,
         };
-        let actual = YIQ::from_rgba(&image::Rgba([0, 0, 0, 0]));
+        let actual = Yiq::from_rgba(&image::Rgba([0, 0, 0, 0]));
         assert_eq!(expected, actual);
     }
 
     #[test]
     fn test_squared_distance_same() {
-        let a = YIQ {
+        let a = Yiq {
             y: 0.5,
             i: -0.1,
             q: 0.1,
         };
-        let b = YIQ {
+        let b = Yiq {
             y: 0.5,
             i: -0.1,
             q: 0.1,

tests/e2e.rs

@@ -148,3 +148,25 @@ fn test_output_image_web_page() {
 
     temp.close().unwrap();
 }
+
+#[test]
+fn test_block_out_area() {
+    let temp = NamedTempFile::new("tiger-blockout-diff.png").unwrap();
+    let mut cmd = Command::cargo_bin("dify").unwrap();
+    let assert = cmd
+        .arg(fs::canonicalize("./benches/fixtures/tiger.jpg").unwrap())
+        .arg(fs::canonicalize("./benches/fixtures/yellow.jpg").unwrap())
+        .arg("--output")
+        .arg(temp.path().display().to_string())
+        .arg("--copy-image")
+        .arg("left")
+        .arg("--block-out")
+        .arg("100,50,350,400");
+
+    assert.assert().failure();
+    temp.assert(predicate::path::eq_file(
+        fs::canonicalize("./benches/fixtures/tiger-blockout-diff.png").unwrap(),
+    ));
+
+    temp.close().unwrap();
+}