Transcript Document 7756749

Discrete Techniques
Chapter 7
Begun February 22, 2005
Finished April 26, 2005
Buffers
 Frame buffer consists of
 Front color buffer
 Back color buffer
 Depth buffer
 Each buffer has the dimensions (n x m) of the
display window.
 The depth (k) of each buffer can vary. For RGB,
it would be the number of bits per color X 3
colors.
 Bitplane refers to any of the k n x m planes.
Digital Images
 Glubyte myColorImage
[512][512][3];
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Glubyte myGrayImage [512][512];
Creating Digital Images
 With an algorithm.
 From data.
 From standard image formats.
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GIF
TIFF
PS
EPS
JPEG
OpenGL does not support image formats.
 From graphics system.
Writing Into Buffers
 Bitblt write operation
 Write_block(
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source /* buffer */,
n /* nrows */,
m /* ncols */,
x /* lower left x pos */,
y /* lower left y pos */,
destination /* buffer */,
u /* destination pos x */,
v /* destination pos y */);
Writing Modes
 Define write
 Simple assignment
 x1 = x2
 Replacement function
 d = f(d, s)
Writing With XOR
 Most interesting function
 Painting Application
 S  S xor M
 M  S xor M
 S  S xor M
Bit and Pixel Operations in
OpenGL
 Defines an internal cursor
 glRasterPos3f(x, y, z);
 glBitmap(width, /* # bits wide */
height, /* # bits high */
x0, /*offset from current raster
position */
y0, /* offset from current rster
position */
xi, /* x increment */
Xy, /* y increment */
Raster Fonts
Pixels and Images
Lookup Tables
Buffers for Picking
Mapping Methods
Texture Mapping
2D Texture Mapping
Texture Mapping in OpenGL
Texture Objects and
Multitexturing
Texture Generation
Environmental Maps
Bump Maps
Compositing Techniques
Opacity and Blending
Image Compositing
Blending and Compositing in
OpenGL
Antialiasing
Back-to-front and Front-toback Rendering
Depth Cue and Fog
Multirendering and the
Accumulation Buffer
Scene Antialiasing
Bump Mapping and
Embossing
Image Processing
Image Extensions
Other Multipass Methods
Sampling and Antialiasing
Sampling Theory
Reconstruction
Quantization
 Each sample must be quantized into k
discrete levels.
 Analog Scale - whole number of lbs
 Image - pixel color
 Binary image - two colors, b/w
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Program 4
 Due March 3, 2005
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Documentation 10%
Style 10%
Compiles 30%
Graphic Output 10%