PICtor PIC image format
Encyclopedia
PICtor is an image file format developed by John Bridges
, the principal author of PCPaint
, the first Paintbrush program for the PC. It was also the native file format for Pictor Paint
and GRASP (multimedia authoring software) (also by Bridges) and became the first widely accepted DOS
imaging standard.
; the file header stores information about the display hardware (screen resolution, color depth
and palette information, bit planes and so on) separately from the actual image information, allowing the image to be properly transferred and displayed on computer systems with different hardware. PIC files commonly stored palette-indexed images ranging from 2 or 4 colors to 16 and 256 colors, although the format has been extended to record true-color (24-bit) images as well.
Although it is device-independent, the PIC format also contains additional information about the device that it was created on, which sometimes leads PCPaint Pictor PIC files to be described as a "device-dependent" format. The encoding of a PIC file is also optimized for decoding quickly onto the native device that it was created-on.
PICtor image data is compressed using an advanced form of encoding
, and a parent-child blockbased algorithm which collapses series of consecutive bytes with identical colors into an encoded child block within a parent block while also allowing non-consecutive bytes to be included as raw data within the same parent block.
As the file is processed during decoding
, the child blocks in each parent block are unpacked either into an off-screen buffer if not displaying in native mode
, or directly into the display adapter if in native mode (which results in quicker unpacking).
John Bridges
John Bridges may refer to:*John Bridges * John E. Bridges, Chelan County Superior Court Judge in Washington state* John Bridges , British archer who competed at the 1908 Summer Olympics...
, the principal author of PCPaint
PCPaint
PCPaint was the first IBM PC-based mouse driven GUI paint program . It was developed by John Bridges and Doug Wolfgram.The hardware manufacturer Mouse Systems bundled PCPaint with millions of computer mice that they sold, making PCPaint also the best-selling MS-DOS-based paint program of the late...
, the first Paintbrush program for the PC. It was also the native file format for Pictor Paint
Pictor Paint
Pictor Paint was an improved version of PCPaint, the first IBM PC-based mouse driven GUI paint program. It was written by John Bridges, the primary author of PCPaint, and bundled with GRASP GRaphical System for Presentation also written by John Bridges...
and GRASP (multimedia authoring software) (also by Bridges) and became the first widely accepted DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
imaging standard.
Typical file format
The PICtor format is a device-independent raster image formatRaster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
; the file header stores information about the display hardware (screen resolution, color depth
Color depth
In computer graphics, color depth or bit depth is the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. This concept is also known as bits per pixel , particularly when specified along with the number of bits used...
and palette information, bit planes and so on) separately from the actual image information, allowing the image to be properly transferred and displayed on computer systems with different hardware. PIC files commonly stored palette-indexed images ranging from 2 or 4 colors to 16 and 256 colors, although the format has been extended to record true-color (24-bit) images as well.
Although it is device-independent, the PIC format also contains additional information about the device that it was created on, which sometimes leads PCPaint Pictor PIC files to be described as a "device-dependent" format. The encoding of a PIC file is also optimized for decoding quickly onto the native device that it was created-on.
PICtor image data is compressed using an advanced form of encoding
Example Pictor Encoder
- Pictor PCPaint PIC image format :PICtor is an image file format developed by John Bridges, the principal author of PCPaint, the first Paintbrush program for the PC...
, and a parent-child blockbased algorithm which collapses series of consecutive bytes with identical colors into an encoded child block within a parent block while also allowing non-consecutive bytes to be included as raw data within the same parent block.
As the file is processed during decoding
Example Pictor Decoder
- Pictor PCPaint PIC image format :PICtor is an image file format developed by John Bridges, the principal author of PCPaint, the first Paintbrush program for the PC...
, the child blocks in each parent block are unpacked either into an off-screen buffer if not displaying in native mode
Native mode
The term native mode or native code is used in computing in two related senses.*to describe something running on a computer natively or in native mode meaning that it is running without any external support as contrasted to running in emulation....
, or directly into the display adapter if in native mode (which results in quicker unpacking).
External links
- Pictor PC Paint File Format Summary
- GRASP File Format Summary
- PCPAINT/Pictor Page Format Description. Format by John Bridges. Document by Microtex Industries, Inc. Revision Date: 2/9/88
- GL — Another animation format. Dr. Martin Reddy (Technical Lead, R & D, Pixar Animation Studios). The Graphics File Formats Page
- The formats of GRASP animation files, by George Phillips