PICT
Encyclopedia
PICT is a graphics
file format
introduced on the original Apple Macintosh computer as its standard metafile
format. It allows the interchange of graphics (both bitmap
ped and vector
), and some limited text support, between Mac applications, and was the native graphics format of QuickDraw
.
The original version, PICT 1, was designed to be as compact as possible while describing vector graphics. To this end, it featured single byte opcode
s, many of which embodied operations such as "do the previous operation again". As such it was quite memory efficient, but not very expandable. With the introduction of the Macintosh II
and Color QuickDraw
, PICT was revised to version 2. This version featured 16-bit opcodes and numerous changes which enhanced its utility. PICT 1 opcodes were supported as a subset for backward compatibility.
Within a Mac application, any sequence of drawing operations could be simply recorded/encoded to the PICT format by opening a "Picture", then closing it after issuing the required commands. By saving the resulting byte stream as a resource
, a PICT resource resulted, which could be loaded and played back at any time. The same stream could be saved to a data file on disk (with 512 bytes of unused header space added) as a PICT file.
With the change to Mac OS X
and deprecation of QuickDraw, PICT was dropped in favour of Portable Document Format
(PDF) as the native metafile format, though PICT support is retained by many applications as it is so widely supported on the Mac.
Computer graphics
Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....
file format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
introduced on the original Apple Macintosh computer as its standard metafile
Metafile
Metafile is a generic term for a file format that can store multiple types of data. This commonly includes graphics file formats. These graphics files can contain raster, vector, and type data...
format. It allows the interchange of graphics (both bitmap
Bitmap
In computer graphics, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to...
ped and vector
Vector graphics
Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
), and some limited text support, between Mac applications, and was the native graphics format of QuickDraw
QuickDraw
QuickDraw is the 2D graphics library and associated Application Programming Interface which is a core part of the classic Apple Macintosh operating system. It was initially written by Bill Atkinson and Andy Hertzfeld. QuickDraw still exists as part of the libraries of Mac OS X, but has been...
.
The original version, PICT 1, was designed to be as compact as possible while describing vector graphics. To this end, it featured single byte opcode
Opcode
In computer science engineering, an opcode is the portion of a machine language instruction that specifies the operation to be performed. Their specification and format are laid out in the instruction set architecture of the processor in question...
s, many of which embodied operations such as "do the previous operation again". As such it was quite memory efficient, but not very expandable. With the introduction of the Macintosh II
Macintosh II
The Apple Macintosh II was the first personal computer model of the Macintosh II series in the Apple Macintosh line and the first Macintosh to support a color display.- History :...
and Color QuickDraw
QuickDraw
QuickDraw is the 2D graphics library and associated Application Programming Interface which is a core part of the classic Apple Macintosh operating system. It was initially written by Bill Atkinson and Andy Hertzfeld. QuickDraw still exists as part of the libraries of Mac OS X, but has been...
, PICT was revised to version 2. This version featured 16-bit opcodes and numerous changes which enhanced its utility. PICT 1 opcodes were supported as a subset for backward compatibility.
Within a Mac application, any sequence of drawing operations could be simply recorded/encoded to the PICT format by opening a "Picture", then closing it after issuing the required commands. By saving the resulting byte stream as a resource
Resource fork
The resource fork is a construct of the Mac OS operating system used to store structured data in a file, alongside unstructured data stored within the data fork. A resource fork stores information in a specific form, such as icons, the shapes of windows, definitions of menus and their contents, and...
, a PICT resource resulted, which could be loaded and played back at any time. The same stream could be saved to a data file on disk (with 512 bytes of unused header space added) as a PICT file.
With the change to Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
and deprecation of QuickDraw, PICT was dropped in favour of Portable Document Format
Portable Document Format
Portable Document Format is an open standard for document exchange. This file format, created by Adobe Systems in 1993, is used for representing documents in a manner independent of application software, hardware, and operating systems....
(PDF) as the native metafile format, though PICT support is retained by many applications as it is so widely supported on the Mac.