feat: new image_quality and sixel_fraction options to allow users to configure the image preview quality (#576)

yazi-adaptor/src/image.rs

@@ -2,7 +2,7 @@ use std::{fs::File, io::BufReader, path::{Path, PathBuf}};
 
 use anyhow::Result;
 use exif::{In, Tag};
-use image::{imageops::{self, FilterType}, io::Limits, DynamicImage, ImageFormat};
+use image::{codecs::jpeg::JpegEncoder, imageops::{self, FilterType}, io::Limits, DynamicImage};
 use ratatui::layout::Rect;
 use yazi_config::{PREVIEW, TASKS};
 use yazi_shared::term::Term;
@@ -20,23 +20,32 @@ impl Image {
 		.await??;
 
 		let (mut w, mut h) = (PREVIEW.max_width, PREVIEW.max_height);
-		tokio::task::spawn_blocking(move || {
-			if (5..=8).contains(&orientation) {
-				(w, h) = (h, w);
-			}
+		if (5..=8).contains(&orientation) {
+			(w, h) = (h, w);
+		}
 
+		let buf = tokio::task::spawn_blocking(move || {
 			if img.width() > w || img.height() > h {
 				img = img.resize(w, h, FilterType::Triangle);
 			}
 
 			img = Self::rotate(img, orientation);
-			Ok(match img {
-				DynamicImage::ImageRgb8(buf) => buf.save_with_format(cache, ImageFormat::Jpeg),
-				DynamicImage::ImageRgba8(buf) => buf.save_with_format(cache, ImageFormat::Jpeg),
-				buf => buf.into_rgb8().save_with_format(cache, ImageFormat::Jpeg),
-			}?)
+			if !matches!(img, DynamicImage::ImageRgb8(_) | DynamicImage::ImageRgba8(_)) {
+				img = DynamicImage::ImageRgb8(img.into_rgb8());
+			}
+
+			let mut buf = Vec::new();
+			JpegEncoder::new_with_quality(&mut buf, PREVIEW.image_quality).encode(
+				img.as_bytes(),
+				img.width(),
+				img.height(),
+				img.color(),
+			)?;
+			Ok::<_, anyhow::Error>(buf)
 		})
-		.await?
+		.await??;
+
+		Ok(tokio::fs::write(cache, buf).await?)
 	}
 
 	pub(super) async fn downscale(path: &Path, rect: Rect) -> Result<DynamicImage> {
@@ -49,15 +58,19 @@ impl Image {
 		.await??;
 
 		let (mut w, mut h) = Self::max_size(rect);
-		tokio::task::spawn_blocking(move || {
-			if (5..=8).contains(&orientation) {
-				(w, h) = (h, w);
-			}
+		if (5..=8).contains(&orientation) {
+			(w, h) = (h, w);
+		}
 
+		// Fast path.
+		if img.width() <= w && img.height() <= h && orientation <= 1 {
+			return Ok(img);
+		}
+
+		tokio::task::spawn_blocking(move || {
 			if img.width() > w || img.height() > h {
 				img = img.resize(w, h, FilterType::Triangle)
 			}
-
 			Ok(Self::rotate(img, orientation))
 		})
 		.await?
@@ -73,6 +86,12 @@ impl Image {
 	}
 
 	async fn orientation(path: &Path) -> Result<u8> {
+		// We don't want to read the orientation of the cached image that has been
+		// rotated in the `Self::precache()` step.
+		if path.parent() == Some(&PREVIEW.cache_dir) {
+			return Ok(0);
+		}
+
 		let path = path.to_owned();
 		tokio::task::spawn_blocking(move || {
 			let file = std::fs::File::open(path)?;
@@ -96,23 +115,16 @@ impl Image {
 	// https://magnushoff.com/articles/jpeg-orientation/
 	fn rotate(mut img: DynamicImage, orientation: u8) -> DynamicImage {
 		let rgba = img.color().has_alpha();
-		if orientation == 2 {
-			img = DynamicImage::ImageRgba8(imageops::flip_horizontal(&img));
-		} else if orientation == 3 {
-			img = DynamicImage::ImageRgba8(imageops::rotate180(&img));
-		} else if orientation == 4 {
-			img = DynamicImage::ImageRgba8(imageops::flip_horizontal(&img));
-		} else if orientation == 5 {
-			img = DynamicImage::ImageRgba8(imageops::rotate90(&img));
-			img = DynamicImage::ImageRgba8(imageops::flip_horizontal(&img));
-		} else if orientation == 6 {
-			img = DynamicImage::ImageRgba8(imageops::rotate90(&img));
-		} else if orientation == 7 {
-			img = DynamicImage::ImageRgba8(imageops::rotate270(&img));
-			img = DynamicImage::ImageRgba8(imageops::flip_horizontal(&img));
-		} else if orientation == 8 {
-			img = DynamicImage::ImageRgba8(imageops::rotate270(&img));
-		}
+		img = match orientation {
+			2 => DynamicImage::ImageRgba8(imageops::flip_horizontal(&img)),
+			3 => DynamicImage::ImageRgba8(imageops::rotate180(&img)),
+			4 => DynamicImage::ImageRgba8(imageops::flip_horizontal(&img)),
+			5 => DynamicImage::ImageRgba8(imageops::flip_horizontal(&imageops::rotate90(&img))),
+			6 => DynamicImage::ImageRgba8(imageops::rotate90(&img)),
+			7 => DynamicImage::ImageRgba8(imageops::flip_horizontal(&imageops::rotate270(&img))),
+			8 => DynamicImage::ImageRgba8(imageops::rotate270(&img)),
+			_ => img,
+		};
 		if !rgba {
 			img = DynamicImage::ImageRgb8(img.into_rgb8());
 		}

yazi-adaptor/src/sixel.rs

@@ -4,6 +4,7 @@ use anyhow::{bail, Result};
 use color_quant::NeuQuant;
 use image::DynamicImage;
 use ratatui::layout::Rect;
+use yazi_config::PREVIEW;
 use yazi_shared::term::Term;
 
 use crate::{adaptor::Adaptor, Image, CLOSE, ESCAPE, START};
@@ -44,7 +45,7 @@ impl Sixel {
 
 		tokio::task::spawn_blocking(move || {
 			let img = img.into_rgba8();
-			let nq = NeuQuant::new(10, 256 - alpha as usize, &img);
+			let nq = NeuQuant::new(PREVIEW.sixel_fraction as i32, 256 - alpha as usize, &img);
 
 			let mut buf: Vec<u8> = Vec::with_capacity(1 << 16);
 			write!(buf, "{}P0;1;8q\"1;1;{};{}", START, img.width(), img.height())?;

yazi-config/preset/yazi.toml

@@ -17,6 +17,8 @@ tab_size        = 2
 max_width       = 600
 max_height      = 900
 cache_dir       = ""
+image_quality   = 75
+sixel_fraction  = 15
 ueberzug_scale  = 1
 ueberzug_offset = [ 0, 0, 0, 0 ]
 

yazi-config/src/preview/preview.rs

@@ -1,9 +1,10 @@
 use std::{fs, path::PathBuf, process, time::{self, SystemTime}};
 
 use serde::{Deserialize, Serialize};
+use validator::Validate;
 use yazi_shared::fs::expand_path;
 
-use crate::{xdg::Xdg, ARGS, MERGED_YAZI};
+use crate::{validation::check_validation, xdg::Xdg, ARGS, MERGED_YAZI};
 
 #[derive(Debug, Serialize)]
 pub struct Preview {
@@ -13,6 +14,9 @@ pub struct Preview {
 
 	pub cache_dir: PathBuf,
 
+	pub image_quality:  u8,
+	pub sixel_fraction: u8,
+
 	pub ueberzug_scale:  f32,
 	pub ueberzug_offset: (f32, f32, f32, f32),
 }
@@ -23,7 +27,7 @@ impl Default for Preview {
 		struct Outer {
 			preview: Shadow,
 		}
-		#[derive(Deserialize)]
+		#[derive(Deserialize, Validate)]
 		struct Shadow {
 			tab_size:   u8,
 			max_width:  u32,
@@ -31,11 +35,18 @@ impl Default for Preview {
 
 			cache_dir: Option<String>,
 
+			#[validate(range(min = 50, max = 90))]
+			image_quality:  u8,
+			#[validate(range(min = 10, max = 20))]
+			sixel_fraction: u8,
+
 			ueberzug_scale:  f32,
 			ueberzug_offset: (f32, f32, f32, f32),
 		}
 
 		let preview = toml::from_str::<Outer>(&MERGED_YAZI).unwrap().preview;
+		check_validation(preview.validate());
+
 		let cache_dir =
 			preview.cache_dir.filter(|p| !p.is_empty()).map_or_else(Xdg::cache_dir, expand_path);
 
@@ -63,6 +74,9 @@ impl Default for Preview {
 
 			cache_dir,
 
+			image_quality: preview.image_quality,
+			sixel_fraction: preview.sixel_fraction,
+
 			ueberzug_scale: preview.ueberzug_scale,
 			ueberzug_offset: preview.ueberzug_offset,
 		}