PICT is a file format that was developed by Apple Computer in 1984 as the native format for Macintosh graphics. PICT files are encoded in QuickDraw commands. The PICT file format is a meta-format that can be used for both bitmap images and vector images.
PICT files are primarily used to exchange graphics between various Macintosh applications. Although these can include prepress applications, it is generally a better idea to use the TIFF or EPS file format in prepress.
In its current operating system, Mac OS X, Apple has replaced PICT by PDF. This means that the use of the PICT file format for exchanging data has diminished tremendously. Early 2009 Adobe decided to partially drop support for PICT in future releases of Photoshop. This means that PICT has effectively become a ‘dinosaur file format’ – to be avoided whenever possible.
File format specs
Let’s take a closer look at some of the specifics of the PICT file format:
- PICT images are storable as a Macintosh resource of type ‘PICT’ or as a data file of type ‘PICT’.
- The object oriented file can contain all the QuickDraw commands used to draw the image on the Macintosh screen (Font: Size, Style, type; Lines, circles, BitMaps, etc…).
- PICT files can contain bitmaps which are either line-art, grayscale or RGB data. PICT files containing only one bitmap are also supported under Windows using QuickTime for Windows.
- A preview image is stored in the file as a PICT resource file. Custom ICON’s are created and stored in the resource file which the Finder of System 7 or later will display.
There are two different versions of the PICT format:
- PICT 1 format: This old format only allowed for 8 colors and none of the modern colour primitives. It was developed for the original black-and-white Macs.
- PICT 2 format: Any type of bitmap objects can be stored in the Macintosh PICT format. The object oriented format of PICT files may include regions, lines, color settings, ovals and other primitives as well as bitmap objects. A PICT file can contain B&W, 4-bit, 8-bit, 16-bit and 24-bit color bitmap objects. 32-bit is supported as well but it is not used for CMYK images, instead it uses the last 8 bits for an alpha-channel (transparency).
Run-length encoding (RLE) is used for compressing bitmaps. With QuickTime V2.0 or later installed, PICT file may also contain JPEG compressed bitmap images. QuickTime comes with routines for compressing PICT files using JPEG compression or any other QuickTime compressor. Any application that uses PICT files on Macintosh with QuickTime installed can decompress these files.
Developer: Apple Computer
Release date: 1984
Type of data: vector & bitmap
Number of colors: 2, 16, 256, 32768 or 16777216
Color spaces: grayscale, RGB
Compression algorithms: Packbits, JPEG
Ideal use: information exchange between non-prepress Macintosh applications
Extension on PC-platform: .PCT
Macintosh file type: PICT
Special features: -
Remarks: replaced by PDF in Mac OS X. More information about the PICT 2 format can be found in the book ‘Inside Macintosh, Volume 5′. The Macintosh Technical note #27 also describes PICT. PICT-JPEG is described in detail in the book ‘Inside Macintosh: Quicktime’.