Implemented different dithering algorithm with brightness check.

src/dithering.rs

@@ -1,44 +1,31 @@
-use image::DynamicImage;
+use image::{
+    DynamicImage, GrayImage,
+    imageops::{self, colorops},
+};
+pub fn auto_brighten(gray: &mut GrayImage) -> () {
+    let avg = gray.pixels().map(|p| p.0[0] as u32).sum::<u32>() / gray.len() as u32;
+
+    if avg < 100 {
+        colorops::brighten_in_place(gray, 40);
+        colorops::contrast_in_place(gray, 25.0);
+    } else if avg > 180 {
+        colorops::brighten_in_place(gray, -15);
+    }
+}
+
+pub fn dither(gray: &mut GrayImage) -> Vec<u8> {
+    imageops::dither(gray, &imageops::colorops::BiLevel);
 
-pub fn atkinson_mono(img: &DynamicImage) -> Vec<u8> {
-    let mut gray = img.to_luma8();
     let (w, h) = (gray.width() as usize, gray.height() as usize);
     let pitch = (w + 7) >> 3;
     let mut bits = vec![0u8; pitch * h];
-    let buf = gray.as_mut();
 
     for y in 0..h {
-        let row = y * w;
         for x in 0..w {
-            let i = row + x;
-            let old = buf[i];
-            let new = if old < 128 { 0 } else { 255 };
-            buf[i] = new;
-            let bit = new == 0;
-            if bit {
-                let byte = y * pitch + (x >> 3);
-                bits[byte] |= 128 >> (x & 7);
-            }
-            let err = ((old as i16) - (new as i16)) / 8;
-
-            if x + 1 < w {
-                buf[i + 1] = (buf[i + 1] as i16 + err).clamp(0, 255) as u8;
-            }
-            if x + 2 < w {
-                buf[i + 2] = (buf[i + 2] as i16 + err).clamp(0, 255) as u8;
-            }
-            if y + 1 < h {
-                let down = i + w;
-                if x > 0 {
-                    buf[down - 1] = (buf[down - 1] as i16 + err).clamp(0, 255) as u8;
-                }
-                buf[down] = (buf[down] as i16 + err).clamp(0, 255) as u8;
-                if x + 1 < w {
-                    buf[down + 1] = (buf[down + 1] as i16 + err).clamp(0, 255) as u8;
-                }
-                if y + 2 < h {
-                    buf[down + w] = (buf[down + w] as i16 + err).clamp(0, 255) as u8;
-                }
+            let byte = y * pitch + (x >> 3);
+            let bit = 7 - (x & 7);
+            if gray[(x as u32, y as u32)].0[0] == 0 {
+                bits[byte] |= 1 << bit;
             }
         }
     }

src/escpos/job.rs

@@ -1,4 +1,7 @@
-use crate::{dithering::atkinson_mono, escpos::errors::EscPosError};
+use crate::{
+    dithering::{auto_brighten, dither},
+    escpos::errors::EscPosError,
+};
 use image::{DynamicImage, imageops::FilterType};
 
 #[repr(u8)]
@@ -26,7 +29,11 @@ pub enum ImageOrientation {
     Largest,
 }
 #[repr(u8)]
-pub enum JustifyOrientation {}
+pub enum JustifyOrientation {
+    Left = 0,
+    Center = 1,
+    Rigth = 2,
+}
 
 #[repr(u8)]
 pub enum TextEffect {
@@ -59,7 +66,7 @@ impl Job {
         let amount = amount.unwrap_or(1);
         self.content.extend_from_slice(&[0x1B, b'd', amount])
     }
-    // pub fn write_text(&mut self, text: String, )
+    pub fn write_text(&mut self, text: String) {}
     pub fn write_bitmap(
         &mut self,
         img: &DynamicImage,
@@ -91,7 +98,10 @@ impl Job {
             DynamicImage::ImageRgba8(image::imageops::resize(img, w, h, FilterType::Triangle));
 
         let img = if swap { img.rotate90() } else { img };
-        let mono = atkinson_mono(&img);
+        let mut gray = img.to_luma8();
+        auto_brighten(&mut gray);
+
+        let mono = dither(&mut gray);
         let width_bytes = ((w + 7) >> 3) as u16;
 
         let buf = &mut self.content;

src/main.rs

@@ -10,36 +10,35 @@ use crate::escpos::{
 };
 
 fn main() {
-    // let args: Vec<String> = env::args().collect();
-    //
-    // let len = args.len();
-    // if len < 2 || len > 2 {
-    //     println!("Please provide a path to the image.");
-    //     process::exit(1);
-    // }
-    //
-    // let img = ImageReader::open(&args[1])
-    //     .map_err(|err| ImageError::IoError(err))
-    //     .and_then(|v| v.decode())
-    //     .unwrap();
+    let args: Vec<String> = env::args().collect();
+
+    let len = args.len();
+    if len < 2 || len > 2 {
+        println!("Please provide a path to the image.");
+        process::exit(1);
+    }
+
+    let img = ImageReader::open(&args[1])
+        .map_err(|err| ImageError::IoError(err))
+        .and_then(|v| v.decode())
+        .unwrap();
 
     let mut printer = Printer::new(384);
     let job = printer.new_job().unwrap();
-    job.write_qr("https://pornhub.com".to_string(), None, None)
-        // .unwrap();
-        // job.write_barcode(
-        //     "kleintje".to_string(),
-        //     Some(10),
-        //     None,
-        //     Some(BARTextPosition::Both),
-        //     Some(BARType::CODE128),
-        // )
-        .unwrap();
-    job.content.extend_from_slice(&[b'\n', b'\n']);
-    // job.write_bitmap(&img, None, None).unwrap();
+    job.write_feed(Some(2));
+    // job.write_barcode(
+    //     "kleintje".to_string(),
+    //     Some(10),
+    //     None,
+    //     Some(BARTextPosition::Both),
+    //     Some(BARType::CODE128),
+    // )
+    // .unwrap();
+    job.write_bitmap(&img, None, None).unwrap();
+    job.write_feed(Some(2));
     job.ready = true;
 
-    println!("{}", printer.queue.len());
+    // println!("{:?}", job.content);
 
     let mut out = std::fs::File::create("/dev/usb/lp0").unwrap();
     printer.print_job(&mut out).unwrap();