Future Additions to Grafica Obscura

Paul Haeberli

Oct 1994

I'm feverishly HTML hacking to make pages on the following topics available. I should get to one of these topics every week or so.

Anti-aliased Text

A demonstration of how anti-aliased text looks with 2, 3, 4, 8, 16, or 128 levels of gray.

2-D Interpolation for Image Processing

Take a color image, create a blurred version of the original, and a B/W version of the original. Place these in a triangular configuration. tile the plane with copies derived by linearly interpolating and extrapolating these "key" images in 2 dimensions.

Visual Acuity Test

Put up two images on a page, one filtered to eliminate spatial frequencies above a period of 4 pixels. Let people view the images and determine for themselves the distance at which the two images look identical. This distance can be used to calculate the visual acuity of the viewer in cycles/degrees. This can be also used to determine an upper bound for the resolution needed for desktop displays.

An Edible Language

A linguistic interpretation of complex foods. Different foods act as nouns. Combination and transformation operations act as verbs.

Conman - A Connection Manager

An interactive data-flow environment for computer graphics. Using graphically interconnected processes to create and modify interactive graphics applications. This was originally published in Siggraph.

Impression - Abstract Image Representations

A simple technique for generating painted representations of photographs. This was originally published in Siggraph.

Image Processing Hacks

NoiseZoom - adding noise to images after resizing.
LineZoom - thresholding images after resizing to make nice line art.
BrightCorr - correcting for variations in illumination in images.
BspImage - using binary trees to subdivide an image using image variance.

GLwords

A collection of words that relate to light and start with the letters "GL".

Matrix Operations for Image processing

Using 4 by 4 matricies to manipulate color images.

A Note on Units of Time

Did you know that a day consists of 46,656,000,000 moments?

Synthetic Marbled Paper

Creating marbled paper using a series of 2D mapping functions.

StyLine and Hatch

Several techniques for creating stylized hidden line drawings of 3D geometric objects. A method for creating hatched shading is also shown.

6 Point Perspective

A way of making 360 degree fish eye pictures of 3D geometry.

Making and Using Environment Maps

Ways of using wide angle lenses or mirrored spheres to make cubical environment maps. Fold-up paper cubical environment images will also be available.

TinyPix

Exploring the limits or tiny picture printing.

Parametric Manufacture

Using laser cutting, fax, and mail order to support desktop design and manufacture.

Reverse Story Boards

Going from film or video to arrays of still images.

Perfect Polka Dot Patterns

Using toroidal Poisson disk distributions to generate perfect polka dot patterns.

PixDump

Making arbitrary binary files visible as arrays of pixels. This can be used to view UNIX executables, the file system and more.

NetWatch

A simple program for visualizing network traffic on the IRIS.

NoiseWarp

Using Perlin noise functions to warp images.

ChromaBlur

A demonstration of how color perception works.

Weave

An interactive weaving simulator.

StretchEncode

Using geometric distortions to print several messages in one area.

WhitePoint

See how your visual system adapts to different lighting conditions.