Pixalated Image Bug

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plxkarl

Pixalated Image Bug

Post by plxkarl »

Hey,

I've been using

ImageMagick 6.3.1 01/12/07 Q16

on my php4 server and everything was working properly, I've moved my website to php5 server and installed

ImageMagick 6.3.9 03/03/08 Q16

Now when I use functions such as MagickReadImage and after MagickWriteImage (magickwand extension v0.1.9) just for some images (maybe 5% of jpg image i upload) it changes the way my image looks... example below:

Original image:
Image

Uploaded Image
Image

Did anybody experience that problem? Can it be fixed in any way?

These are some more examples of what it does to those images:
Image
Image
plxkarl

Re: Pixalated Image Bug

Post by plxkarl »

Anybody had the same problem I did?
plxkarl

Re: Pixalated Image Bug

Post by plxkarl »

bump...
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magick
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Posts: 11064
Joined: 2003-05-31T11:32:55-07:00

Re: Pixalated Image Bug

Post by magick »

We can not reproduce the problem you posted. You will need to post an image and a script that can use to reliably reproduce the pixelation. Once we can reproduce the problem we should have a fix for you within a day or two.
plxkarl

Re: Pixalated Image Bug

Post by plxkarl »

I found the bug. This happens when resizing images from small to large size (streatching them)...

This is the function that causes it...

MagickResizeImage($r, $w, $h, MW_CubicFilter, $blur)

When uploading the following image:

Image

On my php4 server that function produced the following image (Proper):

Image

Same function on my php5 server produces:

Image
User avatar
magick
Site Admin
Posts: 11064
Joined: 2003-05-31T11:32:55-07:00

Re: Pixalated Image Bug

Post by magick »

So far we cannot reproduce the problem. What is the value of your blur parameter? It probably should be 1.0. Also, try the Lanzcos filter and see if that makes a difference.
plxkarl

Re: Pixalated Image Bug

Post by plxkarl »

Thanks, MW_LanczosFilter has fixed the problem.
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