Week 1 (Part:1 Intro)
What is Photoshop?
Adobe Photoshop, or simply Photoshop, is the most powerful graphics editing program developed and published by Adobe Systems. It is the current market leader for commercial bitmap and image manipulation software, and is the flagship product of Adobe Systems. It has been described as "an industry standard for graphics professionals"
Photoshop 1.0 was released in 1990 for Macintosh exclusively. Currently, it is in it's 11th major release with Photoshop CS4. In 2005, Adobe rebranded it's major software titles as a package entitled "Creative Suite", hence the CS. This CS rebranding also resulted in Adobe offering numerous software packages containing multiple Adobe programs for a reduced price. Adobe Photoshop is included in most of Adobe's Creative Suite offerings.
Photoshop's popularity, combined with its high retail price, makes Photoshop's piracy rate relatively high. Adobe countered by including SafeCast DRM starting with Adobe Photoshop CS.
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, and Fireworks. 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.
The .PSB (Large Document Format) format is a newer version of .PSD designed for files over 2 gigabytes.
Photoshop is a pixel-based image editor, unlike Adobe Illustrator, which is a vector-based image editor.
What is a raster/pixel based graphic/image?
(Also known as bitmaps)
Bitmaps are digital graphic files made up of pixels. (Short for picture element) These pixels are like little squares all lined up adjacent to one another in rows and columns. Each of these pixels has a specific color value. When these pixels are viewed on a device, such as a monitor, they create the image or pattern that you see. Photographs are the usual instance where bitmaps are used.
What is a vector image or graphic?
Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon(s), which are all based on mathematical equations, to represent images in computer graphics.
Vector graphic files store the lines, shapes and colours that make up an image as mathematical formulae. A vector graphics program uses these mathematical formulae to construct the screen image, building the best quality image possible, given the screen resolution. Because the actual vector file is not resolution dependent, you can scale your graphic as large as you want with no degradation in quality, which is not the case with bitmaps.