First commit

lid

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+#!/usr/bin/python3
+# lid: lo-fi image dithering
+# written by sloum
+# licence: public domain - use it, improve it, share it!
+#########
+
+from PIL import Image
+import sys
+import os.path
+
+# Main program to output the new image
+def dither(r):
+    im = Image.open(r["path"]).convert("L")
+    width, height = im.size
+    new = create_image(width, height)
+    newpixels = new.load()
+
+    dots = [
+        [64, 128],
+        [192, 0]
+    ]
+
+    count = 0
+    print("    dithering...\033[?25l", end="")
+    for row in range(0, height):
+        if not row % 7:
+            print_spinner(count)
+            count += 1
+            if count > 3:
+                count = 0
+        for col in range(0, width):
+            dotrow = 1 if row % 2 else 0
+            dotcol = 1 if col % 2 else 0
+            impx = get_pixel(im, col, row)
+            newpixels[col, row] = int(impx > dots[dotrow][dotcol])
+
+    new.save("{}.{}".format(r["out"], r["-f"]), r["-f"].upper(), optimize=True, quality=25)
+    print("\033[20C\nfinished\033[?25h")
+
+def print_spinner(n):
+    parts = ["-   "," -  ","  - ","   -"]
+    print("\r{}".format(parts[n]), end="")
+
+# Create a new image with the given size
+def create_image(i, j):
+    image = Image.new("1", (i, j))
+    return image
+
+
+# Get the pixel from the given image
+def get_pixel(image, i, j):
+    width, height = image.size
+    if i > width or j > height:
+        return None
+
+    # Get Pixel
+    pixel = image.getpixel((i, j))
+    return pixel
+
+
+def display_help():
+    helptext = """
+    lid - lo-fi image dithering
+
+    syntax:
+    lid [option]... [infile] [outfile]
+
+    options:
+    -f          output format. defaults to the recommended setting: png
+    -q          image quality. defaults to 90. only has effect on png/jpg
+
+    arguments:
+    infile      path to a valid image file on your system
+    outfile     file name to output, do not include file extension
+
+    example usage:
+    lid -f jpeg -q 75 ~/my_picture.png my_dithered_picture
+    """
+    print(helptext)
+
+
+# Get and validate the arguments
+# returns dict or None
+def parse_input():
+    args = sys.argv[1:]
+    argmap = {
+        "-f": "png",       # output format
+        "-q": 90,          # optimization quality
+        "path": None,      # path to file
+        "out": "lid_file" # output filename
+    }
+    if len(args) < 1:
+        print("lid error: expected image filepath, received None")
+        return None
+
+    if "help" in args or "-h" in args or "--help" in args:
+        display_help()
+        sys.exit(1)
+
+    item = None
+    for x in args:
+        if x in argmap:
+            item = x
+            continue
+        elif item:
+            argmap[item] = x
+            item = None
+        elif len(x) > 0 and x[0] == "-":
+            print("lid error: unknown flag {}".format(x))
+            return None
+        else:
+            if argmap["path"]:
+                argmap["out"] = x
+            else:
+                argmap["path"] = x
+
+    if not argmap["-f"] in ["jpeg", "jpg", "png", "gif", None]:
+        print("lid error: invalid format requested with -f flag. Options: jpeg, png, gif. Defaults to png")
+        return None
+    elif argmap["-f"] == "jpg":
+        argmap["-f"] = "jpeg"
+
+    try:
+        argmap["-q"] = int(argmap["-q"])
+        if argmap["-q"] < 1 or argmap["-q"] > 100:
+            print("lid error: -q value must be between 1 and 100")
+            return None
+    except ValueError:
+        print("lid error: -q value must be an integer")
+        return None
+
+    if not argmap["path"] or not os.path.isfile(argmap["path"]):
+        print("lid error: invalid filepath")
+        return None
+
+    return argmap
+
+if __name__ == "__main__":
+    request = parse_input()
+    if request:
+        dither(request)
+        sys.exit(0)
+    sys.exit(1)