File format extension plug-ins for Adobe Photoshop.

Photoshop is definitely one of the best raster image editors and it probably supports all image types you'll need for your work. So if someone says, that Photoshop need a plug-in, because it doesn't support some of the needed type it may sound like heresy. But, don't hurry. There is still a chance, that you'll find an image with a weird extension, or you'll need to save image with particular settings...and suddenly find out, that Photoshop doesn't support them. (By the way, if you think that there are few image file formats, take a look at http://www.openwith.org/categories/images) Moreover, what will you do, if you need to apply some of the very-very-photoshop-like features to the image, which has nothing in common with raster, like SVG or DXF for example

There are tons of plug-ins for Photoshop around the web. Here I'd like to present you some of format extension plug-ins, which I found useful and some, that just add additional possibilities to work with common Photoshop supported types.

Note: I was using Adobe Photoshop CS4, so some of good plug-ins for CS3 and earlier versions of Creative Suite, which doesn't support CS4, are not listed, because I couldn’t try them.

1.SVG Kit for Adobe Creative Suite(http://svg.scand.com) is a plug-in, which adds support of SVG images to Adobe Photoshop. Adobe’s support of SVG files format is limited, so it is possible to work with SVG directly only in Adobe Illustrator. SVG Kit gives opportunity to open SVG image like any other supported one. In addition, SVG image is automatically decomposed to couple of layers, so you can work with them separately.

System requirements: Windows and Mac OS X 32 and 64 bit. Adobe Photoshop CS3, CS4 and CS5.
Price: 99$ per licence. 30 days full-functional trial available.

2.Electric Image (EIAS) Format (http://www.telegraphics.com.au/sw/info/eiformat.html) is image format plug-in, which allows to open files, created by Electric Image Animation System (http://www.eitechnologygroup.com/). Also reads .EIZ ElectricImage Z-buffer depth files. According to the developers tests, works 100 times faster then the Adobe's plug-in.
System requirements: Windows and Mac OS. Almost all versions of Photoshop, depending on the type of operating system

3.PNGOUT Plug-in for Adobe Photoshop (http://www.ardfry.com/png-plugin/) allows to work with some unsupported types of PNG images (like PNG8 files with transparency), and gives additional save options. (like, for example adding or removing some kind of image chunk)
System requirements: Windows and Mac OS X. Adobe Photoshop CS to CS5.
Price: 29,95$

4.ProEXR (http://www.fnordware.com/ProEXR/) greatly expands on Photoshop's standard openEXR plug-in functionality. In addition allows to save layered EXR files, chose from different compression options, when saving and do some other things.
System requirements: Windows and Mac OS. Photoshop CS3 or higher.
Price: 95$. 15 days full-functional trial available.

5.Sibcode Icon plugin for Photoshop (http://www.sibcode.com/icon-plugin/), gives you all necessary tools for creating .ico images. It works with multi-format icons, transparency and semi-transparency etc. You can both export and import .ico image and use this plug-in with some other software like Elements, AfterEffects, Premiere etc.
System requirements: Windows only. Photoshop CS or higher.
Price: Free.

6.Blow Up 2 (http://www.alienskin.com/blowup/index.aspx). Not sure, whether it is correct to place it here, but the plug-in helps to smooth over one of the worst problems of raster files: quality loss on resizing. By temporary converting image to vector representation, it makes “zoomed in” parts look better, so can be useful for preparing hard copy of the image.
System requirements: Windows and Mac Os X. Photoshop CS2-CS5
Price: 149-249$

7.SiteGrinder 2 (http://www.medialab.com/sitegrinder3/) “Web designers and developers, don't go by”. The plug-in, which builds web sites from multilayer Photoshop documents. The plug-in creates CSS , controls and other staff from the PSD multilayer image.
System requirements: Windows and Mac Os X. Photoshop 6.x-CS4
Price: 129-349$

8.SuperPNG (http://www.fnordware.com/superpng/) is a free Adobe Photoshop plug-in for using PNG ("ping") files. Compared to native Adobe's PNG plug-in it saves considerably smaller PNGs. Note, that I couldn't download it from the main site, so you can find it with the help of search engines.
System requirements: Windows and Mac Os. Photoshop 5.5 or higher.
Price: Free.

9.j2k (http://www.fnordware.com/j2k/) Nice and small plug-in, that allows to open/save JPEG 2000files. Compared to standard JPERG its comrade offers better quality and smaller file size. System requirements are also Photoshop 5.5 and After Effects 4.0 but it worked well. However you'll be able to find several similar plug-ins if you want.
System requirements: Windows and Mac Os. Photoshop 5.5 or higher.
Price:Free.