Faster blur

Author: kornelski

src/denoise.rs

@@ -270,15 +270,31 @@ macro_rules! median_channel {
             if $top.next.a > 0 { $top.next.$chan } else { $mid.curr.$chan },
             if $mid.prev.a > 0 { $mid.prev.$chan } else { $mid.curr.$chan },
             $mid.curr.$chan, // if the center pixel is transparent, the result won't be used
-            $mid.curr.$chan, // more weight on the center
             if $mid.next.a > 0 { $mid.next.$chan } else { $mid.curr.$chan },
             if $bot.prev.a > 0 { $bot.prev.$chan } else { $mid.curr.$chan },
             if $bot.curr.a > 0 { $bot.curr.$chan } else { $mid.curr.$chan },
             if $bot.next.a > 0 { $bot.next.$chan } else { $mid.curr.$chan },
-        ].select_nth_unstable(5).1
+        ].select_nth_unstable(4).1
     }
 }
 
+/// Average of 9 neighboring pixels
+macro_rules! blur_channel {
+    ($top:expr, $mid:expr, $bot:expr, $chan:ident) => {{
+        let mut tmp = 0u16;
+        tmp += u16::from(if $top.prev.a > 0 { $top.prev.$chan } else { $mid.curr.$chan });
+        tmp += u16::from(if $top.curr.a > 0 { $top.curr.$chan } else { $mid.curr.$chan });
+        tmp += u16::from(if $top.next.a > 0 { $top.next.$chan } else { $mid.curr.$chan });
+        tmp += u16::from(if $mid.prev.a > 0 { $mid.prev.$chan } else { $mid.curr.$chan });
+        tmp += u16::from($mid.curr.$chan); // if the center pixel is transparent, the result won't be used
+        tmp += u16::from(if $mid.next.a > 0 { $mid.next.$chan } else { $mid.curr.$chan });
+        tmp += u16::from(if $bot.prev.a > 0 { $bot.prev.$chan } else { $mid.curr.$chan });
+        tmp += u16::from(if $bot.curr.a > 0 { $bot.curr.$chan } else { $mid.curr.$chan });
+        tmp += u16::from(if $bot.next.a > 0 { $bot.next.$chan } else { $mid.curr.$chan });
+        (tmp / 9) as u8
+    }}
+}
+
 pub(crate) fn smart_blur(frame: ImgRef<RGBA8>) -> ImgVec<RGB8> {
     let mut out = Vec::with_capacity(frame.width() * frame.height());
     loop9_img(frame, |_,_, top, mid, bot| {
@@ -288,7 +304,25 @@ pub(crate) fn smart_blur(frame: ImgRef<RGBA8>) -> ImgVec<RGB8> {
             let median_b = median_channel!(top, mid, bot, b);
 
             let blurred = RGB8::new(median_r, median_g, median_b);
-            // diff limit, because median removes thin lines too
+            if color_diff(mid.curr.rgb(), blurred) < 16*16*6 {
+                blurred
+            } else {
+                mid.curr.rgb()
+            }
+        } else { RGB8::new(255,0,255) });
+    });
+    ImgVec::new(out, frame.width(), frame.height())
+}
+
+pub(crate) fn less_smart_blur(frame: ImgRef<RGBA8>) -> ImgVec<RGB8> {
+    let mut out = Vec::with_capacity(frame.width() * frame.height());
+    loop9_img(frame, |_,_, top, mid, bot| {
+        out.push_in_cap(if mid.curr.a > 0 {
+            let median_r = blur_channel!(top, mid, bot, r);
+            let median_g = blur_channel!(top, mid, bot, g);
+            let median_b = blur_channel!(top, mid, bot, b);
+
+            let blurred = RGB8::new(median_r, median_g, median_b);
             if color_diff(mid.curr.rgb(), blurred) < 16*16*6 {
                 blurred
             } else {

src/lib.rs

@@ -514,14 +514,14 @@ impl Writer {
     }
 
     fn make_resize(inputs: Receiver<CatResult<InputFrameUnresized>>, diff_queue: OrdQueue<InputFrame>, settings: &SettingsExt) -> CatResult<()> {
-        minipool::new(settings.max_threads.min(if settings.s.fast { 6 } else { 4 }.try_into().unwrap()), "resize", move |to_remap| {
+        minipool::new(settings.max_threads.min(if settings.s.fast || settings.extra_effort { 6 } else { 4 }.try_into().unwrap()), "resize", move |to_remap| {
             for frame in inputs {
                 to_remap.send(frame?)?;
             }
             Ok(())
         }, move |frame| {
             let resized = resized_binary_alpha(frame.frame, settings.s.width, settings.s.height)?;
-            let frame_blurred = smart_blur(resized.as_ref());
+            let frame_blurred = if settings.extra_effort { smart_blur(resized.as_ref()) } else { less_smart_blur(resized.as_ref()) };
             diff_queue.push(frame.frame_index, InputFrame {
                 frame: resized,
                 frame_blurred,