Adobe Photoshop, or simply Photoshop, is a graphics editing program developed and published by Adobe Systems. It is the current and primary market leader for commercial bitmap and image manipulation, and is the flagship product of Adobe Systems. It has been described as "an industry standard for graphics professionals" and was one of the early "killer applications" on Macintosh.

Features :

Photoshop has strong ties with other Adobe software for media editing, animation, and authoring. Files in Photoshop's native format, .PSD, can be exported to and from Adobe ImageReady, Adobe Illustrator, Adobe Premiere Pro, After Effects, and Adobe Encore DVD to make professional standard DVDs and provide non-linear editing and special effects services, such as backgrounds, textures, and so on, for television, film, and the Web. For example, Photoshop CS broadly supports making menus and buttons for DVDs. For .PSD files exported as a menu or button, it only needs to have layers, nested in layer sets with a cuing format, and Adobe Encore DVD reads them as buttons or menus.

Photoshop can utilize the color models RGB, lab, CMYK, grayscale, binary bitmap, and duotone. Photoshop has the ability to read and write raster and vector image formats such as: .EPS, .PNG, .GIF, .JPEG, Fireworks, etc. It also has several native file formats:

The .PSD (Photoshop Document) format stores an image with support for most imaging options available in Photoshop. These include layers with masks, color spaces, ICC profiles, transparency, text, alpha channels and spot colors, Clipping paths, and duotone settings. This is in contrast to many other file formats (e.g. .EPS or .GIF) that restrict content to provide streamlined, predictable functionality. Photoshop's popularity means that the .PSD format is widely used, and it is supported to some extent by most competing software.

CS3

Smart Layers display the filter without altering the original image
Photoshop CS3 is marketed with three main components of improvement over previous versions: "Work more productively, Edit with unrivaled power, and composite with breakthrough tools." New features propagating productivity include streamlined interface, improved Camera Raw, better control over print options, enhanced PDF support, and better management with Adobe Bridge. Editing tools new to CS3 are the Clone Source palette and nondestructive Smart Filters, and other features such as the Brightness/Contrast adjustment and Vanishing Point module were enhanced. The Black and White adjustment option improves users control over manual grayscale conversions with a dialog box similar to that of Channel Mixer. Compositing is assisted with Photoshop's new Quick Selection and Refine Edge tools and improved image stitching technology.

CS3 Extended contains all features of CS3 plus tools for editing and importing some 3D graphics file formats, enhancing video, and comprehensive image analysis tools, utilizing MATLAB integration and DICOM file support.

Plugins
Photoshop functionality can be extended by add-on programs called Photoshop plugins which act like mini-editors that modify the image. The most common type are filter plugins that provide various image effects. They are located in the 'Filter' menu: pre-installed plugins come first, and third-party plugins are placed below the separator.

Online Tutorials of Adobe Photoshop : Click Here