Resize Produces Half Empty PNG's in Firefox, Safari Blank

[merrick]

Debian 2.4.27-3-386
PHP 4.4.4-8+etch3
Imagemagick 6.2.4.5.dfsg1-0.14
Apache 2.2.3-4

Source File:
http://www.sandiegoish.com/imagemagick/140.png
Resized Problem File:
http://www.sandiegoish.com/imagemagick/140_240.png
Resized Smaller OK File:
http://www.sandiegoish.com/imagemagick/140_75.png

When I use the following commands on a PNG, the resize to 240x240 produces a half empty image or non displayable image on Firefox, Safari, Preview and Photoshop on a Mac. It will not even handle the resized image. For some reason, resize with dimensions of 75x75 produces a displayable image. I have exported the same image from Photoshop using numerous combinations of PNG settings with and without transparency and get the same results. All commands I use produce GIF's and JPEG's that display properly.

copy($image_file, $image_thumb_240);
copy($image_file, $image_thumb_75);
exec( "mogrify -resize '240x240>' $image_thumb_240 &" );
exec( "mogrify -resize '75x75>' $image_thumb_75 &" );
chmod($image_thumb_240, 0440);
chmod($image_thumb_75, 0440);

I also tried and encountered the same problem with the convert command below.

exec( "convert $image_file -resize '240x240' $image_thumb_240&" );

Any ideas on how to resolve this would be greatly appreciated. Hopefully it's not a bug, in which case sorry for the wrong category posting. I did search through the archives and Google before posting here.

[magick]

Add +repage after the -resize option. Let us know if that fixes the problem you reported.

[merrick]

Thank you, I tried the following and the resized image is still not displaying properly or at all.

exec( "mogrify -resize '240x240>' $image_thumb_240 +repage &" );

[magick]

The repage option must appear *before* the output image filename.

[merrick]

Oops, I tried this and the image does not display, same result.

exec( "mogrify -resize '240x240>' +repage $image_thumb_240 &" );

[magick]

We cannot reproduce the problem you are having. You could try the latest ImageMagick release, 6.3.6-3.

[merrick]

Thank you for trying, I will try updating.

I did try resizing the image on an older redhat server running an older version of ImageMagick and that worked fine.

[merrick]

Apologies for the bug in my code that prompted this thread. As you stated, there is no problem like I described within ImageMagick.

After lots of wrangling with packages and code, I found the problem in my php code that displayed the image. It was getting the incorrect file size, that of the original file. The problem appeared when I uploaded small files 5kb or so, and when the smaller dimensioned, resized file, grew to a larger file size (10kb after resize).

My php code would only display 5kb of a 10kb file. When I right clicked and saved the file through the browser, I was storing a garbage file. When I attempted to view such garbage file, firefox showed as many bytes of the file as my php code said it was. When I tried safari it did not display an image, nor did photoshop or preview.

Just thought I should wrap it up, again sorry for the hassle.

[kunderez]

Download this image
... and run following command

Code: Select all

convert Papua_New_Guinea_map.png +repage PNG:magic_happens.png

.. then you'll see what merrick was experiencing(?)...

My solution to this strange behaviour was to add "-type TrueColor" ... so running the following command gives me the desired results

Code: Select all

convert Papua_New_Guinea_map.png -type TrueColor +repage PNG:magic_happens_not.png

ImageMagick Version: ImageMagick 6.2.8 10/20/10 Q16
Platform: Linux 2.6.18-238.9.1.el5 #1 SMP Tue Apr 12 18:10:13 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux

[glennrp]

Please upgrade to a recent version of ImageMagick (6.7.0-x). The bug you
observed was fixed somewhere in the 6.6.x series.

A PNG of PNG... nice.