SuperPaint
SuperPaint was an early painting program and part of a larger graphics system that also included specially designed hardware. It was designed by Richard Shoup at Xerox PARC from 1972 to 1975 and developed with the participation of Alvy Ray Smith , Bob Flegal and Patrick Baudelaire . The first picture created with SuperPaint was taken in early April 1973.
User interface
SuperPaint ran on a Data General Nova 800 computer which used a then new type of graphics tablet for drawing and had several floppy disk drives for loading and saving images. Great emphasis was placed on ease of use. The user interface consisted of three screens with a resolution of 640 × 480 pixels each and a color depth of 4 bits, which made 16 different colors possible. One screen showed the work area, another the menu with the editing tools and the currently selected color; the third was used to enter file names via a command line and to output brief operating instructions, depending on the selected tool.
The colors were selected using the HSB color space . SuperPaint made it possible, among other things, to draw and erase lines, create custom brushes and fill areas . Further functions were the enlargement and reduction of pictures, the copying or moving of parts of the picture, the insertion of text or the replacement of colors. It was also possible to load an image via a video interface. Simple animations were also possible through color cycling , the rotation of a maximum of ten color palette entries. Shoup later also wrote routines for antialiasing .
technology
The SuperPaint system used one of the first frame buffers to store the currently displayed image. This memory, which allowed a resolution of 640 × 480 pixels with an 8-bit color depth, consisted of 16 circuit boards with a total capacity of 307,200 bytes and was grouped in two identical memory banks . The entire memory was produced using MOS - shift registers synchronously rotated on the screen to display the image. The color of a particular pixel could only be changed when it was rotated to the correct position. Color look-up tables made up of 256 × 8 × 3 static RAM modules were used to display the color - indexed image. Two multiplexers controlled the data flow pixel by pixel. The first selected the input data of the frame buffer between the computer, video input or the frame buffer (for rotation). The second controlled the input of the color tables and thus the output of the digital-to-analog converter and the screen output .
The static image was overlaid by the movable cursor or brush of any shape , which was not stored in the framebuffer, but delivered by the relatively slow main processor . So that its image data could be delivered in real time, it was run-length coded and then decompressed in memory. In the case of the opaque pixels of the cursor, a switch was made from the first multiplexer to the second in order to output the image data of the cursor.
BCPL and assembly language were used as programming language . The system has been changed and expanded several times over the years to enable additional functions.
Use and influence
While SuperPaint was primarily intended for research purposes, it was used for a number of projects until the late 1970s. One of the first computer graphics for television broadcasts were in the late 1970s by Damon Rarey for the PBS telecast OverEasy created with the help of Super Paint, including eye-catching many animations. The cost of creating these graphics was significantly lower than with conventional design methods. From the end of 1978 Damon Rarey produced dozens of graphics with SuperPaint to visualize space probe maneuvers as part of the Pioneer Venus mission.
For his pioneering work in the development of digital painting programs, Shoup received an Emmy in 1983 and an Oscar for Science and Development in 1998 with Alvy Ray Smith and Thomas Porter .
The SuperPaint system is still functional and is now in the Computer History Museum , California.
literature
- Richard Shoup: Color table animation. ACM SIGGRAPH Computer Graphics 13, 2 (Aug 1979): 8-13, ISSN 0097-8930
- Richard Shoup: “SuperPaint”… The Digital Animator. Datamation 25, 5 (May 1979): 150-156, ISSN 0011-6963
- Richard Shoup: SuperPaint: An Early Frame Buffer Graphics System. IEEE Annals of the History of Computing 23, 2 (Apr – Jun 2001): 32–37, ISSN 1058-6180 ( PDF, 950 KB )