def debug_image(image, step=2):
for x in range(0, image.width(), step):
for y in range(0, image.height(), step):
pixel = image.get_pixel(x, y)
red, green, blue, alpha = pixel2channels(pixel)
print "rgba(%s,%s,%s,%s) at %s,%s" % (red, green, blue, alpha, x,
y)
def validate_pixels_are_not_premultiplied2(image):
looks_not_multiplied = False
for x in range(0,image.width(),2):
for y in range(0,image.height(),2):
pixel = image.get_pixel(x,y)
red,green,blue,alpha = pixel2channels(pixel)
#each value of the color channels will never be bigger than that of the alpha channel.
if alpha > 0:
if red > 0 and red > alpha:
print 'red: %s, a: %s' % (red,alpha)
looks_not_multiplied = True
return looks_not_multiplied
def validate_pixels_are_not_premultiplied2(image):
looks_not_multiplied = False
for x in range(0, image.width(), 2):
for y in range(0, image.height(), 2):
pixel = image.get_pixel(x, y)
red, green, blue, alpha = pixel2channels(pixel)
#each value of the color channels will never be bigger than that of the alpha channel.
if alpha > 0:
if red > 0 and red > alpha:
print 'red: %s, a: %s' % (red, alpha)
looks_not_multiplied = True
return looks_not_multiplied
def validate_pixels_are_premultiplied(image):
bad_pixels = []
for x in range(0,image.width(),2):
for y in range(0,image.height(),2):
pixel = image.get_pixel(x,y)
red,green,blue,alpha = pixel2channels(pixel)
if alpha > 0:
pixel = image.get_pixel(x,y)
is_valid = ((0 <= red <= alpha) and is_pre(red,alpha)) \
and ((0 <= green <= alpha) and is_pre(green,alpha)) \
and ((0 <= blue <= alpha) and is_pre(blue,alpha)) \
and (alpha >= 0 and alpha <= 255)
if not is_valid:
bad_pixels.append("rgba(%s,%s,%s,%s) at %s,%s" % (red,green,blue,alpha,x,y))
num_bad = len(bad_pixels)
return (num_bad == 0,bad_pixels)
def validate_pixels_are_not_premultiplied(image):
over_alpha = False
transparent = True
fully_opaque = True
for x in range(0,image.width(),2):
for y in range(0,image.height(),2):
pixel = image.get_pixel(x,y)
red,green,blue,alpha = pixel2channels(pixel)
if alpha > 0:
transparent = False
if alpha < 255:
fully_opaque = False
color_max = max(red,green,blue)
if color_max > alpha:
over_alpha = True
return over_alpha or transparent or fully_opaque
def validate_pixels_are_not_premultiplied(image):
over_alpha = False
transparent = True
fully_opaque = True
for x in range(0, image.width(), 2):
for y in range(0, image.height(), 2):
pixel = image.get_pixel(x, y)
red, green, blue, alpha = pixel2channels(pixel)
if alpha > 0:
transparent = False
if alpha < 255:
fully_opaque = False
color_max = max(red, green, blue)
if color_max > alpha:
over_alpha = True
return over_alpha or transparent or fully_opaque
def validate_pixels_are_premultiplied(image):
bad_pixels = []
for x in range(0,image.width(),2):
for y in range(0,image.height(),2):
pixel = image.get_pixel(x,y)
red,green,blue,alpha = pixel2channels(pixel)
if alpha > 0:
pixel = image.get_pixel(x,y)
is_valid = ((0 <= red <= alpha) and is_pre(red,alpha)) \
and ((0 <= green <= alpha) and is_pre(green,alpha)) \
and ((0 <= blue <= alpha) and is_pre(blue,alpha)) \
and (alpha >= 0 and alpha <= 255)
if not is_valid:
bad_pixels.append("rgba(%s,%s,%s,%s) at %s,%s" % (red,green,blue,alpha,x,y))
num_bad = len(bad_pixels)
return (num_bad == 0,bad_pixels)
def debug_image(image,step=2):
for x in range(0,image.width(),step):
for y in range(0,image.height(),step):
pixel = image.get_pixel(x,y)
red,green,blue,alpha = pixel2channels(pixel)
print "rgba(%s,%s,%s,%s) at %s,%s" % (red,green,blue,alpha,x,y)
