I was having trouble displaying thumbnails using the free version, as described in this posrt: forum.joomlaworks.net/index.php?topic=8734.msg33847#msg33847

After exhausting several possibilities I found out that thumbnails are only displayed for JPEG images, but not for PNG and GIF files. Is this correct? Does the limitation apply also to the Premium version of SIG? I'd be happy to buy the Pro edition, but I do need PNG support.

(On edit: png and gif support is enabled in GD library)

Bump. I really need to know about png support in the commercfial version. Unless there is a full-featured trial version of SIG Pro?

I really don't see why you can't see PNG thumbnails to your site, because they are supported in both plugins (free and commercial). Could you provide a link to your site to try to locate the problem?

Hi Yiota, thanks for replying.

An example page is
ethervane.com/new-products/estopwatch/screenshots-estopwatch

The three thumbnails you see are jpeg files. Next to each is a tiny white square - these should be thumbnails of png versions of the same images. I get the same effect in Firefox 3.0 and IE 7, with no ad blockers installed. And I get exactly the same effect on a local installation of Joomla (Apache on WinXP, slightly older build of PHP). GIF thumbnails are not shown, either (I don't need them at the moment, but FYI).

This is running on PHP Version 5.2.9 with the following GD info:

gd
GD Support enabled
GD Version bundled (2.0.34 compatible)
FreeType Support enabled
FreeType Linkage with freetype
FreeType Version 2.1.7
GIF Read Support enabled
GIF Create Support enabled
JPG Support enabled
PNG Support enabled
WBMP Support enabled
XBM Support enabled

Please let me know if you need any more information.

(I got an email notification of your reply, but there was no new post when I checked. Did you have a chance to investigate? Thanks a lot for any help.)

Could you also PM me access to your administration?

Could you also PM me access to your administration?

Done, and thanks!

Hi there!

Could you please give the method witch you've used to create the png file?

I downloaded the png image and I've used it at my local system.
The server returns me the error message
Probably, this issue has to do with the software used for the pngs.
Could you please post the software and the options used for the creation of the png?

Thank you!

Could you please give the method witch you've used to create the png file?

Hi!

The pngs were created with FastStone Screen Capture program. They open fine with any graphics viewer or editor I have (ACDSee 10, IrfanView, Picasa, etc), and show correctly in Firefox 3 and IE 7, too.

I've tried another experiment. I took a jpeg photo from my camera, reduced in size, and saved it as png in five different apps: ACDSee, IrfanView, Paint Shop Pro 8, Adobe Fireworks and Paint Net. I have uploaded them to a new test page on the server, along with the original jpeg file. The effect is the same: only the jpeg file generates a thumbnail:

ethervane.com/gallery-test-01

(On the test page, the filename of each image indicates the program used to generate the png. Clicking each missing thumbnail displays the corresponding image correctly. The original is at the bottom.)

Well, I believe I found a workaround!

Since PHP v5.1 the GD function imagepng() accepts compression argument. The compression argument must be from 0 to 9. 4images is using the compression settings when creating thumbnails or image resizing for jpeg images which can be from 0 to 100. Because of that using imagepng() function will return fatal error ( source )

You have to modify the plugin_jw_sig/showthumb.php file.

At the end of the file you'll see the codechange ti with that
Check it out and tell us if it works for you too!

Thank you!