I tried, but I cannot reproduce this. Can you provide any more information about versions and platforms?
Here's mine: >>> platform.platform() 'Linux-2.6.35-30-generic-x86_64-with-Ubuntu-10.10-maverick' >>> sys.version '2.6.6 (r266:84292, Sep 15 2010, 16:22:56) \n[GCC 4.4.5]' >>> pygame.ver '1.9.1release' I rendered a bunch of circles at various sizes and brightness on a purple background, like your example: import pygame import pygame.gfxdraw width = 640 height = 480 # canvas screen = pygame.display.set_mode((width, height)) # background screen.fill([47, 40, 54]) # dot y = 32 radius = 4 color = [64, 64, 64, 255] for radius in xrange(4,20): y += 2*radius + 2 for brightness, x in enumerate(xrange(10,700,2*radius+2)): color = [brightness, brightness, brightness, 255] pygame.gfxdraw.aacircle(screen, x, y, radius, color) pygame.gfxdraw.filled_circle(screen, x, y, radius, color) pygame.display.flip() pygame.image.save(screen, "screenshot.png") raw_input() This is what I got: https://lh4.googleusercontent.com/-1WIwoTVKZPk/TiLmc5DifmI/AAAAAAAAA_U/uvawJt7daWE/s800/screenshot.png Nice visualization, by the way. Very smart-looking. On Sun, Jul 17, 2011 at 1:32 PM, Marian Steinbach <mar...@sendung.de> wrote: > Hi! > > I'm new to pygame and just used it for the first time for data > visualization. See the result here: http://vimeo.com/26157684 > > The visualization consists of anti-aliased dots in various shades of > gray on a purple background. > > Dark grey dots have unwanted blue pixels on their edges, which I > cannot explain. You can see them especially in the upper part of the > video. > > Here is what I'm doing to draw the background and dots: > > # canvas > screen = pygame.display.set_mode((width, height)) > > # background > self.screen.fill([47, 40, 54]) > > # dot > radius = 4 > color = [64, 64, 64, 255] > pygame.gfxdraw.aacircle(screen, x, y, radius, color) > pygame.gfxdraw.filled_circle(screen, x, y, radius, color) > > > > Any ideas where the blue pixels come from? > > Thanks! > > Marian >