Full Name	Mac PICT
Format ID	IG_FORMAT_PCT = 30
File Extension(s)	*.pct, *.pict
Data Type	Metafile (2D raster, 2D geometry)
Data Encoding	Binary
Color Profile Support	No
Multi-Page Support	No
Alpha Channel Support	Supports single alpha channel for read only. Alpha channel has to be 8-bit image.
ImageGear Platforms Support	WIN32, WIN64, MAC, UNIX

ImageGear Supported Versions:

• PICT 2 (for Color QuickDraw version 2). Added color and support for additional QuickDraw functions.
• PICT 1 (for Color QuickDraw version 1). Monochrome only.

ImageGear Supported Features:

• IG_FLTR_DETECTSUPPORT - autodetection
• IG_FLTR_PAGEREADSUPPORT - single page file reading
• IG_FLTR_PAGEINSERTSUPPORT - single-page file writing

ImageGear Read Support:

• IG_COMPRESSION_NONE:
  • Indexed RGB: 1, 4, 8 bpp;
  • RGB: 24 bpp and 24+8 bit alpha
• IG_COMPRESSION_RLE:
  • Indexed RGB: 1, 4, 8 bpp;
  • RGB: 24 bpp and 24+8 bit alpha
• IG_COMPRESSION_JPEG:
  • Indexed RGB: 1, 4, 8 bpp;
  • RGB: 24 bpp and 24+8 bit alpha

ImageGear Write Support:

• IG_COMPRESSION_NONE:
  • Indexed RGB: 1, 4, 8 bpp (for 1, 4, 8 bpp, the files are ONLY saved as uncompressed if the image is 64x64 pixels or smaller. Otherwise, the image is saved as RLE compressed).
  • RGB: 24 bpp (Always saved as uncompressed)

ImageGear Filter Control Parameters:

Filter Control Parameter	Type	Default Value	Available Values	Description
FORCE_VERSION	AT_BOOL	FALSE	TRUE, FALSE	TRUE means saving of PCT in version 1.

Comments:

The PICT is one of the most widely-supported graphics file formats for the Macintosh.

PICT files begin with a fixed length header containing application-specific data, followed by fields that store the image size and location. If it is a PICT2 file, an additional header follows that contains the original resolution data of the image.

The bitmap data in the PICT2 format is referred as a Pixmap, from older terminology where Pixmap meant a bitmap with color.

The PICT file uses "opcodes". These are similar to the fields found in most file formats, and are associated with data that describes different shapes, lines, fill patterns, etc.

The lengthy list of opcodes is followed by the bitmap or "pixmap" data that describes the image data's address and resolution. The color table follows the opcodes. Next, source and destination rectangles are defined by their top left and lower right coordinates.

The pixel data, stored in the "PixData" field, is the last data to appear in the file. Each value is an index to the color table. This data is represented by 1, 2, or 4 bits.

References Used

Brown, C. Wayne, and Barry J. Shepherd. Graphics File Formats: Reference and Guide. Greenwich, CT.: Manning Publications, 1992.

Kay, David C. and John R. Levine. Graphics File Formats. Windcrest Books, 1992.

Murray, James D. and William vanRyper. Encyclopedia of Graphics File Formats. Sebastopol, CA: O'Reilly & Associates, Inc., 1994.