Add README

Author: thekovic

README.md

@@ -0,0 +1,16 @@
+# png_defringe_rs
+
+Using PNG Defringe can remove colored fringes from resampled and filtered graphics which have transparency, caused by the filtering picking color information from pixels that are meant to be fully transparent.
+
+## Installation
+
+You don't need to do anything to install png_defringe_rs, all you have to do is grab a release from the Releases page and unzip the archive.
+
+## Usage
+
+    Usage: png_defringe.exe <action> <input_file> <output_file>
+    ---------------------------------------
+    List of actions:
+        black - transparent pixels go towards black
+        avg - transparent pixels go towards the average of all opaque pixels
+        match - transparent pixels are interpolated to match their nearest neighbours

src/main.rs

@@ -135,7 +135,7 @@ fn defringe_to_interpolation(img: &mut ImageBuffer<Rgba<u8>, Vec<u8>>) {
 }
 
 fn print_usage() {
-    println!("Usage: png_defringe <action> <input_file> <output_file>");
+    println!("Usage: png_defringe.exe <action> <input_file> <output_file>");
     println!("---------------------------------------");
     println!("List of actions:");
     println!("\t black - transparent pixels go towards black");