Rogue Pixels in 6.4.8-4

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jorlando

Rogue Pixels in 6.4.8-4

Post by jorlando »

Hi, I installed 6.4.8-4 (coming from 6.4.1) and found that certain fonts when -captioned onto a large canvas, leave a few extra pixels of the fill color at the far right edge of the canvas. This in turn causes issues with the -trim operation since the rogue pixel is the same color as the fill. I opened the trouble fonts in FontCreator and found them to be heavily kerned with a lot of character overlap. Not all heavily kerned fonts seem to have the problem however.

None of this is an issue in 6.4.1

It seems to be font related but 6.4.1 is tolerant while 6.4.8-4 is not.

Any ideas? The blur-fuzz approach doesnt help since only one edge is involved.

Thx
Jeff
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magick
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Re: Rogue Pixels in 6.4.8-4

Post by magick »

Font rendering has multiple layers involved. The metrics are from the font and might have bogus metrics, we render with Freetype and there could be a bug, or perhaps their is a bug in ImageMagick. To investigate we need to reproduce the problem. Post your ImageMagick command here and a URL to your font and resulting image.
jorlando

Re: Rogue Pixels in 6.4.8-4

Post by jorlando »

The problem is shown below. The image created by the command has the white background. The same command run on 6.4.1 has no such pixels and trims right up to the text as expected.

Image

Code: Select all

-size 360x -background \#ffffff -stroke none -fill \#000000 -font /home/.../New/AeroFont.ttf -pointsize 33 -gravity northwest caption:"Rogue Pixel Demo" +repage -trim -bordercolor \#ffffff -border 0
The font that was used is at: http://www.dafont.com/aero-font-one.font?nb_ppp=50

thx
Jeff
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magick
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Posts: 11064
Joined: 2003-05-31T11:32:55-07:00

Re: Rogue Pixels in 6.4.8-4

Post by magick »

We can reproduce the problem you reported. Give us a day or two to produce a patch. Stand by...
jorlando

Re: Rogue Pixels in 6.4.8-4

Post by jorlando »

Hi, Just installed 6.4.8-6 and the issue with rogue pixels appears solved. The fill issue with SVG paths that was fixed with 6.4.8-4 ( viewtopic.php?f=3&t=10594 ) has reappeared however.

If I apply the SVG hack for stroke-opacity described in that same thread ( viewtopic.php?f=3&t=10594 ), second post from the end, both the fill issue and the stroke-opacity issue are resolved.
... change the opacity="0.55" to stroke-opacity="0.55" AND change the order it appears in the code so that stroke-opacity appears after stroke color then it works correctly.

I never had a chance to try 6.4.8-5

rgds
Jeff
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