I have just had a logo designed for my site, I have a photoshop file on a transparent background as well as gifs and jpgs. I am having problems getting the logo to appear clean and sharp on a colored background.
On a white background the logo looks great, but on my webistes colored background the edges look frayed with white noise surrounding the intricate parts of the design.
What should I do to have the logo display cleanly on a coloured background? Thanks
If you have a copy of Photoshop, you can open the photoshop file (assuming it's the original PSD file?), and just create a background layer behind the logo in a color that matches your site's background. Then "flatten" the image, convert it to Indexed Color mode, use the magic wand tool to select and delete the solid area of the background color, and then use the "Save for Web" command to export it as a transparent GIF.
It takes longer to describe than it takes to actually do it, by far... and the "halo" around the edge of the GIF image should now match the background of your site.
If that all sounds greek to you, ask the designer to do it. They should have provided you with a copy that matched your site background to begin with, if that's what you were going to use the image for.
Most logos are created with clean lines, many from vector graphics. If your Photoshop format logo on a transparent background appears to have jagged edges, perhaps it is from a "fade" effect that was applied to the outer edges of the original image, which would cause some of the white noise you described when converted to a .gif file.
The method mivox explained will work well unless a definite fade effect has been applied to the edges. If so, you may need to "feather" your selection (you made with the magic wand tool) a few pixels to soften and smooth the edges of the area you wish to preserve, and also add a degree of transparency that will display better when you place the color you want for your background behind it.
This works best if the original image is a fairly large one.