alpha composits and transposing big image

mosiac.py

@@ -29,7 +29,7 @@ class Mosiac():
 		self.matrixSize = None
 
 
-	def openBigImage(self, imagePath, mat=(20,40)):
+	def openBigImage(self, imagePath, mat=(40,20)):
 		"""
 		Opens and initializes the big image.
 		"""
@@ -77,7 +77,7 @@ class Mosiac():
 			if image.mode == "P":
 				image = image.convert(image.palette.mode)
 			if image.mode == "RGBA":
-				image = alpha_composite_with_color(image).convert("RGB")
+				image = alpha_composite(image).convert("RGB")
 			if image.mode == "L":
 				image = image.convert("RGB")
 			# image = image.convert("RGBA")
@@ -117,6 +117,8 @@ class Mosiac():
 			cluster = {pixel: self.imageBank[pixel] for pixel in \
 				sort[n*num:n*num+num]}
 			self.clusters.append(cluster)
+
+		# shove the left overs into the last cluster
 		self.clusters[-1].update({pixel: self.imageBank[pixel] for pixel in \
 			sort[-(len(sort) % num):]})
 
@@ -143,7 +145,7 @@ class Mosiac():
 		tol = int(len(dist) * self.tolerance)
 		tol += int(tol == 0)
 		indexs = dist.argsort()[:tol]
-		# choice = dist.argmin()  # closet value
+		# choice = indexs.argmin()  # closet value
 		choice = np.random.choice(indexs)
 		return cluster[tuple(nodes[choice])]
 
@@ -156,6 +158,9 @@ class Mosiac():
 		pixels = list(self.smallImage.getdata())
 		for pixel in pixels:
 			image = self.nearestImage(pixel)
+			image = image.convert("RGBA")
+			comp = Image.new("RGBA", image.size, pixel + (30,))
+			image = Image.alpha_composite(image, comp).convert("RGB")
 			self.imageMatrix.append(image)
 		print(f"buildMatrix took: {time.time()-then} seconds.")
 
@@ -166,12 +171,16 @@ class Mosiac():
 		"""
 		then = time.time()
 		image = Image.new("RGB", self.bigImageSize, (255,255,255))
-		# self.bigImage = self.bigImage.crop((0,0,self.bigImageSize[0],self.bigImageSize[1]))
+		self.bigImage = self.bigImage.crop(
+			(0, 0, self.bigImageSize[0], self.bigImageSize[1]))
 		n = 0
 		for y in range(0, self.bigImageSize[1], self.tileSize[1]):
 			for x in range(0, self.bigImageSize[0], self.tileSize[0]):
 				image.paste(self.imageMatrix[n], box=(x,y))
 				n += 1
+		image = image.convert("RGBA")
+		self.bigImage.putalpha(50)
+		image = Image.alpha_composite(image, self.bigImage).convert("RGB")
 		# self.bigImage.save(os.path.join(root, "mosiac.png"), "PNG")
 		image.save(os.path.join(root, "mosiac.jpg"), "JPEG", optimize=True, quality=90)
 		print(f"buildMosiac took: {time.time()-then} seconds.")
@@ -189,46 +198,15 @@ def step (r,g,b, repetitions=1):
 	return (h2, lum, v2)
 
 
-def alpha_composite(front, back):
-	"""Alpha composite two RGBA images.
-
+def alpha_composite(image, color=(255, 255, 255)):
+	"""
+	Alpha composite an RGBA Image with a specified color.
 	Source: http://stackoverflow.com/a/9166671/284318
-
-	Keyword Arguments:
-	front -- PIL RGBA Image object
-	back -- PIL RGBA Image object
-
 	"""
-	front = np.asarray(front)
-	back = np.asarray(back)
-	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)
-
-	"""
-	back = Image.new('RGBA', size=image.size, color=color + (255,))
-	return alpha_composite(image, back)
+	image.load()  # needed for split()
+	background = Image.new('RGB', image.size, color)
+	background.paste(image, mask=image.split()[3])  # 3 is the alpha channel
+	return background
 
 
 if __name__ == "__main__":