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+# Separator
+
+Command line tool to separate an image into background and foreground
+
+## Usage
+
+./main <filename> <new_filename> <fg_color> <bg_color> <new_color>
+
+This will replace <fg_color> with <new_color> and make <bg_color> transparent.
+It only handles two colors but correctly interpolates between the two and adds transparency accordingly.
+Colors are entered as six hex digits without any annotations.
+
+## Example
+```bash
+./main img.png img_separated.png 000000 ffffff ff0000
+```
+
+This works with an image with a black foreground on a white background.
+The resulting image is red with a transparent background.