Photoshop Users Manual 063

©1988 John and Thomas Knoll Preliminary Documentation PhotoShop ™ User's Manual PhotoShop is powerful image processing and photo retouching program. It works with bitmaps, gray level images, indexed color images, and full 24-bit color pictures. Some of the key features are: •Very fast dithering allows the internal data structure to be independent of the display device. This means that you can work with 24-bit images on an 8-bit display, or a mac plus, or anything in between. The program supports 32-bit quickdraw, so that when these devices are available, you can view images directly without dithering. •Speed. All of the retouch, math, resizing, conversion and other calculation tools have been highly optimized. They operate generally much faster than similar programs. •Virtual Memory. Even if the user has very little RAM (1 meg), he can still work with pictures up to 64 megabytes, if there is available disk space. The program will operate faster if there is RAM for the whole picture, but the virtual memory scheme is very fast, and the program remains responsive. This is especially important because of the current high price, and delivery delays of RAM. •Math tools. A large selection of math tools allow the user to add, subtract, multiply, difference, minimum, and maximum any two images.These tools can be strung together to perform very sophisticated operations, such as bluescreen composites or complex feature extraction. •8-bit selection mask. PhotoShop is the only program that offers a multi-bitplane selection mask with a variable feather edge radius. This allows you to feather in brightness and color changes, and do perfectly anti-aliased photo composites. The user can copy information from any channel of the image into the selection mask, or vice versa. For example, if he uses the math tools to extract an anti-aliased matte of some feature in the picture, he can then copy that matte into the selection mask, and use that to cut and paste that feature elsewhere, or adjust color balance of only that selection. •File format support a) large variety makes the program a universal translator. PhotoShop reads AND WRITES: PICT files PICT resources Amiga IFF/ILBM Compuserve GIF MacPaint Thunderscan TIFF RIFF - well OK, not yet, but soon. PIXAR Pixelpaint PhotoShop A very smart and flexible raw format. PhotoShop™ user's manual 26/05/1988 page1 ©1988 John and Thomas Knoll Preliminary Documentation b) Format conversion lets you convert any format into any other. for ex…