PICT

Latest revision as of 12:14, 20 May 2024

PICT, or QuickDraw/PICT, is a graphics format native to Macintosh computers. It is associated with the QuickDraw API.

Though it is a vector format, it is often used as if it were a raster format. Many files contain just a single bitmap image.

PICT format is complicated and quirky. Although plenty of documentation about it exists, there does not appear to be any single source that provides a reasonably clear and complete specification.

[edit] Format details

When PICT is used as a standalone file format, the file usually starts with an unused 512-byte header, usually with all bytes set to 0. When PICT is embedded as a resource inside some other format, this header is usually not present.

[edit] Identification

A version 1 PICT file has (hex) bytes 11 01 at offset 522 (or 10 if there is no header), and should end with ff.

A version 2 PICT file has bytes 00 11 02 ff 0c 00 at offset 522 (or 10 if there is no header), and should end with 00 ff.

[edit] Application data

Custom application data can be stored in PICT files by using the "LongComment" opcode. Each comment has an integer that identifies its "kind".

• A file with a list of comment kinds

Notable comment kinds:

• 100 is an Application Comment (see below).
• 220 is used for ICC profile data.
• 498 appears to be related to Photoshop, though it might also be used for other things.

The "kind" does little to identify the application, or prevent collisions. A better way is to use kind 100, which has a standard way to include a 4-byte application signature.

[edit] Related formats

• Many bitmap images are compressed using PackBits.
• Opcodes 0x8200 and 0x8201 use a format based on QuickTime or QTIF. This, in turn, is often used as a wrapper for an image in JPEG format.
• Macintosh resource file - Often contains "PICT" resources in this format
• PICT is used for graphics stored within Keynote documents.
• Encapsulated PostScript

[edit] Specifications

• Inside Macintosh: Imaging With QuickDraw
• PICT File Format Notes
• Macintosh Technical Note QD14 (a.k.a. TN21): QuickDraw's Internal Picture Definition - PICT version 1 (from archive.org)
• PICT.ZIP - Probably a lot of information here, but in inconvenient formats
• Macintosh Technical Note QD06 (a.k.a TN181): Every Picture [Comment] Tells Its Story, Don't It? - PICT Application Comments (from archive.org)
• HELIOS ICC profile tagging specifications - Tells how to embed an ICC profile in a PICT file

[edit] Software

[edit] Vector-based software

(software that can process PICT vectors as vectors)

• Scribus
• LibreOffice

[edit] Other software

• Netpbm
• ImageMagick (for PICT v2)
• image2pict1 (for PICT v1)
• IrfanView
• Deark (for analysis, resource extraction)
• XnView

[edit] Converting

[edit] Converting from PICT

An image can be converted from a PICT using ImageMagick:

  convert image.pict image.png

This example shows a PNG image as the destination image, but ImageMagick supports many other output formats.

[edit] Converting to PICT

An image can be converted to a PICT using ImageMagick:

  convert image.png image.pict

This example shows a PNG image as the source image, but ImageMagick supports many other input formats.

[edit] Using converted images on a classic Mac system

Once converted, the image can then be added to a HFS disk image using hfsutils:

  hmount disk.img                      # mount the HFS disk
  hcopy ./image.pict :image.pic        # copy the PICT image to the disk
  hattrib -t PICT -c 8BIM :image.pic   # set the type and creator codes to ensure that the image is recognised by Mac OS
  humount                              # unmount the disk

[edit] Sample files

• http://www.fileformat.info/format/macpict/sample/index.htm
• http://cd.textfiles.com/cdreview/cdreview66/PCT01_01/PC0101P/
• http://cd.textfiles.com/fantaziasampler/CLIPART/PCT/ - Version 1
• http://www.ngdc.noaa.gov/mgg/geology/lazarus/ch7/pict_plots/ - Vector-only PICTs
• dexvert samples — image/pict
• Photo Pics PICT format for Macintosh

[edit] Resources

• Macintosh PICT File Format Summary, from the Encyclopedia of Graphics File Formats
• ExifTool: PICT Tags
• Wikipedia article