Opened 14 years ago
Last modified 4 years ago
#7500 assigned enhancement
Image scaling < 1.0 (downsampling) shows aliasing — at Version 1
| Reported by: | aldeck | Owned by: | axeld |
|---|---|---|---|
| Priority: | normal | Milestone: | R1.1 |
| Component: | Servers/app_server | Version: | R1/Development |
| Keywords: | image scaling downsampling aliasing | Cc: | stippi |
| Blocked By: | Blocking: | ||
| Platform: | All |
Description (last modified by )
Image scaling < 1.0 (downsampling) shows aliasing
Can be reproduced with ImageViewer or desktop background with this high resolution test image http://www.eronn.net/camera/test-chart/resolution%20test-chart.jpg (any highres image with sharp contrasted lines will do)
Change History (1)
comment:1 by , 13 years ago
| Cc: | added |
|---|---|
| Description: | modified (diff) |
| Keywords: | aliasing added; moire artifacts removed |
| Summary: | Image scaling (downsampling) shows moire artifacts → Image scaling < 1.0 (downsampling) shows aliasing |
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I haven't had enough time to test what i wanted, though all i can affirm a that point is that the generic agg implementation of DrawBitmap (Painter.cpp) has the problem. Note that i haven't analyzed the algorithms themselves and don't know if they actually support high quality downscaling. Will possibly look further when i make more time.
cc'ing stippi as i'm sure he has a clue