refactored colorization and kwargs

ascii.py

@@ -12,6 +12,7 @@ import numpy as np
 import numpngw
 
 ASCII_CHARS = "$@%#*+=-:. "
+BRAIL_CHARS = "⠿⠾⠼⠸⠰⠠ "
 HEADERS = {'User-Agent': 'Gimme ascii.'}
 
 
@@ -26,43 +27,51 @@ def scale_image(image, maxDim=100):
 	"""
 	original_width, original_height = image.size
 	original_width = original_width * 2
-	if original_width > original_height:
+	if original_width <= maxDim and original_height <= maxDim:
-		if original_width > maxDim:
+		new_width, new_height = image.size
-			new_width = maxDim
+	elif original_width > original_height:
-			aspect_ratio = original_height/float(original_width)
+		new_width = maxDim
-			new_height = int(aspect_ratio * new_width)
+		aspect_ratio = original_height/float(original_width)
-		else:
+		new_height = int(aspect_ratio * new_width)
-			new_width, new_height = image.size
 	else:
-		if original_height > maxDim:
+		new_height = maxDim
-			new_height = maxDim
+		aspect_ratio = original_width/float(original_height)
-			aspect_ratio = original_width/float(original_height)
+		new_width = int(aspect_ratio * new_height)
-			new_width = int(aspect_ratio * new_height)
-		else:
-			new_width, new_height = image.size
 	image = image.resize((new_width, new_height))
 	return image
 
 
-def pixels_to_chars(image, reverse=False):
+def pixels_to_chars(image, scale="ascii", color_code=None):
 	"""
 	Maps each pixel to an ascii char based on where it falls in the range
-	0-255 normalized to the length of ASCII_CHARS.
+	0-255 normalized to the length of the chosen scale.
 	"""
-	range_width = int(255 / len(ASCII_CHARS)) + (255 % len(ASCII_CHARS) > 0)
+	scales = {"ascii": ASCII_CHARS,
+		"ascii_reverse": "".join(reversed(ASCII_CHARS)),
+		"brail": BRAIL_CHARS,
+		"brail_reverse": "".join(reversed(BRAIL_CHARS))}
+
+	color_prefix = {"irc": "\03", "ansi":"\033"}
+
+	range_width = int(255 / len(scales[scale])) + (255 % len(scales[scale]) > 0)
 
 	pixels = list(image.getdata())
-	chars = []
+	pixels = [pixels[i:i + image.size[0]] for i in range(0, len(pixels),
-	for pixel in pixels:
-		if reverse:
-			index = -int(pixel/range_width)-1
-		else:
-			index = int(pixel/range_width)
-		chars.append(ASCII_CHARS[index])
-
-	chars = "".join(chars)
-	chars = [chars[i:i + image.size[0]] for i in range(0, len(chars),
 		image.size[0])]
+
+	chars = []
+	for row in pixels:
+		new_row = ""
+		for pixel in row:
+			R, G, B = pixel
+			L = R * 299/1000 + G * 587/1000 + B * 114/1000
+			index = int(L/range_width)
+			char = scales[scale][index]
+			if color_code and char is not " ":
+				prefix = color_prefix[color_code] + char_color(pixel,color_code)
+				char = prefix + char
+			new_row += char
+		chars.append(new_row)
 	return "\n".join(chars)
 
 
@@ -132,46 +141,75 @@ def open_image(imagePath):
 	return image
 
 
-def colorize(chars, image, code):
+def alpha_composite(front, back):
+	"""Alpha composite two RGBA images.
+
+	Source: http://stackoverflow.com/a/9166671/284318
+
+	Keyword Arguments:
+	front -- PIL RGBA Image object
+	back -- PIL RGBA Image object
+
 	"""
-	Colorizes the ascii matrix. Moves iteratively through the matrix and
+	front = np.asarray(front)
-	calls char_color on each pixel/character. Spaces are skipped to save
+	back = np.asarray(back)
-	time and CPU cycles.
+	result = np.empty(front.shape, dtype='float')
+	alpha = np.index_exp[:, :, 3:]
+	rgb = np.index_exp[:, :, :3]
+	falpha = front[alpha] / 255.0
+	balpha = back[alpha] / 255.0
+	result[alpha] = falpha + balpha * (1 - falpha)
+	old_setting = np.seterr(invalid='ignore')
+	result[rgb] = (front[rgb] * falpha + back[rgb] * balpha * (1 - falpha)) / result[alpha]
+	np.seterr(**old_setting)
+	result[alpha] *= 255
+	np.clip(result, 0, 255)
+	# astype('uint8') maps np.nan and np.inf to 0
+	result = result.astype('uint8')
+	result = Image.fromarray(result, 'RGBA')
+	return result
+
+
+def alpha_composite_with_color(image, color=(255, 255, 255)):
+	"""Alpha composite an RGBA image with a single color image of the
+	specified color and the same size as the original image.
+
+	Keyword Arguments:
+	image -- PIL RGBA Image object
+	color -- Tuple r, g, b (default 255, 255, 255)
+
 	"""
-	prefix = {"irc": "\03", "ansi":"\033"}
+	back = Image.new('RGBA', size=image.size, color=color + (255,))
-	chars = chars.split("\n")
+	return alpha_composite(image, back)
-	for j in range(0, image.size[1]):
-		new_row = ""
-		for k in range(0, image.size[0]):
-			if chars[j][k] == " ":
-				continue
-			new_row += prefix[code] + char_color(image.getpixel((k,j)), code)
-			new_row += chars[j][k]
-		chars[j] = new_row
-
-	chars = "\n".join(chars)
-	if code == "ansi":
-		chars += "\033[0m" # to avoid lingering effects in terminals
-	return chars
 
 
-def image_to_ascii(image, reverse=False, colors=None):
+def image_to_ascii(image=None, **kwargs):
 	"""
 	Reads an image file and converts it to ascii art. Returns a
 	newline-delineated string. If reverse is True, the ascii scale is
 	reversed.
 	"""
+	if not image:
+		image = open_image(kwargs["imagePath"])
+
+	if image.mode == "P":
+		image = image.convert(image.palette.mode)
+	if image.mode == "RGBA":
+		image = alpha_composite_with_color(image).convert("RGB")
+
 	image = scale_image(image)
-	image_grey = image.convert('L')	# convert to grayscale
 
-	chars = pixels_to_chars(image_grey, reverse)
+	if kwargs["brail"]:
+		scale = "brail"
+	else:
+		scale = "ascii"
+	if kwargs["reverse"]:
+		scale += "_reverse"
+
+	chars = pixels_to_chars(image, scale, kwargs["color"])
 
-	if colors:
-		chars = colorize(chars, image, colors)
 	image.close()
-	image_grey.close()
 	del(image)
-	del(image_grey)
 	return chars
 
 
@@ -190,17 +228,17 @@ def ascii_to_image(image_ascii):
 	return image
 
 
-def handle_gif(image, output, reverse=False):
+def handle_gif(**kwargs):
 	"""
 	Handle gifs seperately.
 	"""
-	image = open_image(args.imagePath)
+	image = open_image(kwargs["imagePath"])
 	ascii_seq = []
-	new_image = ascii_to_image(image_to_ascii(image, reverse))
+	new_image = ascii_to_image(image_to_ascii(image, **kwargs))
 	image.seek(1)
 	while True:
 		try:
-			im = ascii_to_image(image_to_ascii(image, reverse))
+			im = ascii_to_image(image_to_ascii(image, **kwargs))
 			ascii_seq.append(im)
 			image.seek(image.tell()+1)
 		except EOFError:
@@ -210,7 +248,7 @@ def handle_gif(image, output, reverse=False):
 		# duration=60, loop=0, optimize=True)
 	ascii_seq = [new_image] + ascii_seq
 	np_ascii_seq = [np.array(im) for im in ascii_seq]
-	with open(output, "wb") as file:
+	with open(kwargs["output"], "wb") as file:
 		numpngw.write_apng(file, np_ascii_seq)
 
 
@@ -234,6 +272,7 @@ if __name__=='__main__':
 	parser.add_argument(
 		"-i",
 		"--image",
+		dest="drawImage",
 		action="store_true",
 		help="Outputs the ascii art as an image rather than text. Requires \
 		--output.")
@@ -260,21 +299,25 @@ if __name__=='__main__':
 		action="store_const",
 		const="irc",
 		help="Shortcut for '--color irc'.")
+	parser.add_argument(
+		"-b",
+		"--brail",
+		action="store_true",
+		help="Uses brail unicode characters instead of ascii characters.")
 	args = parser.parse_args()
 
 	if args.animated:	# --animated includes --image
-		args.image = True
+		args.drawImage = True
-	if args.image:		# --image requires --output
+	if args.drawImage:		# --image requires --output
 		if not args.output:
 			parser.error("--image requires --output")
 
-	image = open_image(args.imagePath)
 	if args.animated:
-		handle_gif(image, args.output, args.reverse)
+		handle_gif(**vars(args))
 		exit()
 
-	image_ascii = image_to_ascii(image, args.reverse, args.color)
+	image_ascii = image_to_ascii(None, **vars(args))
-	if args.image:
+	if args.drawImage:
 		image = ascii_to_image(image_ascii)
 		image.save(args.output, "PNG")
 	elif args.output: