Graphics processing apparatus for producing output data at edges

Details Graphics processing apparatus for producing output data at edges Graphics processing apparatus for producing output data at edges

1991-04-04

1996-09-10

Jankus, Almis R.

Computer graphics processing and selective visual display system

Display driving control circuitry

Controlling the condition of display elements

395128, 395133, 345136, G06T 1100

Patent

active

055553605

ABSTRACT:
A graphics processing apparatus carries out an antialiasing for obtaining an output image having smooth edges, enabling a speedy computation of approximate shading area rates of pixels by making use of neither a subpixel dividing process nor a shading pixel counting process. The apparatus comprises a discriminating part for discriminating the presence of an end point pixel at an edge portion of an image defined by a vector data, a computing part for computing the number of edge pixels by extracting two integer parts a, b from x coordinate values Xa, Xb of two points where a scanline intersects the vector data, a setting part for setting a x coordinate value of the end point pixel to the Xb only when an end point pixel is found at the edge portion, an approximate point part for determining an approximate point value C' from a prescribed factor c.times.(n-1) computed by a decimal fraction c extracted from the x coordinate value Xa, a memory part for storing a lookup table containing a set of predetermined data, and an approximate area factor part for determining an approximate shading area factor k by making reference to the lookup table stored in the memory part.

REFERENCES:
patent: 4843380 (1989-06-01), Oakley et al.
patent: 4890162 (1989-12-01), McNeely et al.
patent: 4918626 (1990-04-01), Watkins et al.
patent: 5220650 (1993-06-01), Barkans
Gupta et al., Filtering Edges for Gray-Scale Displays, Computer Graphics (Aug. 1981).
Franklin C. Crow, "A Comparison of Antialiasing Techniques," IEEE CG & A, vol. 1, No. 1, pp. 40-48.

Affiliated with

Also associated with

Rating

Graphics processing apparatus for producing output data at edges does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Graphics processing apparatus for producing output data at edges, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Graphics processing apparatus for producing output data at edges will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1327493