realbasic-nug
[Top] [All Lists]

Can't properly open GIF files on Windows builds - vdysdokf

To: realbasic-nug at lists dot realsoftware dot com
Subject: Can't properly open GIF files on Windows builds - vdysdokf
From: Chris Smolinski <csmolinski at blackcatsystems dot com>
Date: Sat, 31 Jul 2004 13:43:15 -0400
Delivered-to: realbasic-nug at lists dot realsoftware dot com
References: <20040728220557 dot 8C95A362BEE at lists dot realsoftware dot com>
I spent a little time poking into this problem, to try to see exactly what is happening. Here are my results:

First the easy part, everything works fine on Mac builds ;-)

With a Windows build, if you use OpenAsPicture to create a picture object, and the picture file happens to be a GIF picture, then RB throws away much of the color information. You can be left with a rather ugly looking image.

It appears that the colors in the GIF image get mapped to the nearest colors in a standard Windows 256 color palette. The severity of the problem depends on what type of picture you're dealing with. For some pictures, you may hardly notice it. For others, with a lot of subtle shading of mainly one color, the results are truly horrible. The program of mine which suffers from this problem sadly falls into the latter category.

This happens whether you display the resulting picture in a canvas, or if you use ExportPicture to save it back again to a file in another format. The common thread is OpenAsPicture.

Opening a jpeg file is fine. I even took a gif image that would show the problem severely, converted it to a jpeg file, and then opened that in the RB app, it displayed fine, even with the subtle shading. I created a simple project that shows the problem, and signed on to existing report vdysdokf which seems to be the same issue.

It would be REALnice if this could be fixed in RB 5.5.4 ;-)

--

---
Chris Smolinski
Black Cat Systems
http://www.blackcatsystems.com
_______________________________________________
Unsubscribe or switch delivery mode:
<http://www.realsoftware.com/support/listmanager/>

Search the archives of this list here:
<http://www.realsoftware.com/listarchives/lists.html>

<Prev in Thread] Current Thread [Next in Thread>
  • Can't properly open GIF files on Windows builds - vdysdokf, Chris Smolinski <=