[Image-SIG] PIL 1.1.5 polygon filling off by one vertical pixel, alpha blended drawing?
fredrik at pythonware.com
Thu May 26 08:54:08 CEST 2005
> the ImageDraw.Draw.polygon function does not draw as I expect it.
> Deep down in the C-code some Floor, Ceil and +0.5 seem to combine
> for a strange effect.
can you elaborate: from a quick look, the image seems to match
the code pretty well.
> 1. Any suggestions to actually draw within the outline only?
> 2. Why can't I draw with alpha-blending (it seems like I
> have to im.paste to achieve this -- so inefficient...)
recent versions support RGBA-on-RGB drawing; from the CHANGES
+ Added experimental RGBA-on-RGB drawing support. To use RGBA
colours on an RGB image, pass "RGBA" as the second string to
the ImageDraw.Draw constructor.
> 3. Do I have to destruct the Draw instance with del explicitly
> (like it's done in the example code)
> or is the implicit destruction enough to get it freed?
no. normal garbage collection works here.
> 4. Is ImagePath.Path more efficient or just syntactic sugar?
Path is more efficient if you need to scale/transform the data before
you draw. If you're doing the calculations elsewhere, you can use
any input format.
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