changed to binary format

Cargo.toml

@@ -6,4 +6,4 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-image = "0.23.14"
+image = "0.25.8"

src/main.rs

@@ -1,26 +1,37 @@
 use image::{GenericImageView, Pixel};
 use std::fs::File;
-use std::io::Write;
+use std::io::{BufWriter, Write};
 use std::env;
 
 fn main() -> std::io::Result<()> {
     let args: Vec<String> = env::args().collect();
+    if args.len() != 3 {
+        eprintln!("Usage: {} <input> <output>", args[0]);
+        std::process::exit(1);
+    }
+
     let path = &args[1];
     let out_path = &args[2];
+
     let img = image::open(path).map_err(|e| {
         std::io::Error::new(std::io::ErrorKind::Other, e.to_string())
     })?;
+
     let (width, height) = img.dimensions();
-    let mut file = File::create(out_path)?;
+
+    let file = File::create(out_path)?;
+    let mut writer = BufWriter::new(file);
+
+    writer.write_all(&width.to_le_bytes())?;
+    writer.write_all(&height.to_le_bytes())?;
+
     for y in 0..height {
         for x in 0..width {
-            let pixel = img.get_pixel(x, y);
-            let (r, g, b, _) = pixel.channels4();
-            write!(file, "{}s{}s{}p", r, g, b)?;
+            let px = img.get_pixel(x, y).to_rgb();
+            writer.write_all(&px.0)?; 
         }
-        file.write_all(b"\n")?;
     }
 
+    writer.flush()?;
     Ok(())
 }
-