Created
September 28, 2015 13:42
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| def __mix(back, front, alpha): | |
| result = 0 | |
| result += round(front * (alpha / 255)) | |
| result += round(back * ((255-alpha) / 255)) | |
| return result | |
| colordic = {} | |
| for f in range(256): | |
| for a in range(256): | |
| v1 = __mix(0, f, a) | |
| v2 = __mix(255, f, a) | |
| k = (v1, v2) | |
| if not k in colordic: | |
| colordic[k] = (f, a) | |
| elif colordic[k][1] == a: | |
| pass # we are still okay | |
| else: | |
| pass # This is an error case, but I don't know what to do! | |
| from PIL import Image | |
| def generate_transparent_image(black_img, white_img, out_img): | |
| img1 = Image.open(black_img) | |
| img2 = Image.open(white_img) | |
| img3 = Image.new('RGBA', img1.size, (0,0,0,0)) | |
| px1 = img1.load() | |
| px2 = img2.load() | |
| px3 = img3.load() | |
| for x in range(img1.size[0]): | |
| for y in range(img1.size[1]): | |
| rgb1 = px1[x,y] | |
| rgb2 = px2[x,y] | |
| v1 = rgb1[0] | |
| v2 = rgb2[0] | |
| a = colordic[(v1,v2)][1] | |
| px3[x,y] = rgb1[:3] + (a,) | |
| img3.save(out_img) | |
| def generate_alpha_image(black_img, white_img, out_img): | |
| img1 = Image.open(black_img) | |
| img2 = Image.open(white_img) | |
| img3 = Image.new('RGBA', img1.size, (0,0,0,0)) | |
| px1 = img1.load() | |
| px2 = img2.load() | |
| px3 = img3.load() | |
| for x in range(img1.size[0]): | |
| for y in range(img1.size[1]): | |
| rgb1 = px1[x,y] | |
| rgb2 = px2[x,y] | |
| v1 = rgb1[0] | |
| v2 = rgb2[0] | |
| a = colordic[(v1,v2)][1] | |
| px3[x,y] = (a,a,a,255) | |
| img3.save(out_img) |
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