Search found 3 matches

by stereoMatching
2013-01-25T07:54:31-07:00
Forum: Digital Image Processing
Topic: future of image enlargement?
Replies: 61
Views: 135999

Re: future of image enlargement?

The SR result about the alphabets are very good I could tell what are the alphabets of the last line even with my eyes without relying on OCR, pretty amazing. I remember our professor said that fractal base algorithm is patent? Do that mean we have to pay money if we want to implement this algorithm...
by stereoMatching
2013-01-20T01:17:20-07:00
Forum: Bugs
Topic: Sigmoidal equation(bug?) of image magick
Replies: 7
Views: 6895

Re: Sigmoidal equation(bug?) of image magick

Thanks, the result are much more closer to the equation --(1/(1+exp(10*(.5-u)))-0.0066928509)*1.0092503 Although the last one has some different(precision problem?But double also give the same answer). exponential version inline float sigmoidal(float contrast, float threshold, float signal) { return...
by stereoMatching
2013-01-19T06:49:16-07:00
Forum: Bugs
Topic: Sigmoidal equation(bug?) of image magick
Replies: 7
Views: 6895

Sigmoidal equation(bug?) of image magick

According to this page http://www.imagemagick.org/Usage/color_mods/#sigmoidal The equation of the sigmoidal should be (1/(1+exp(β*(α-u))) - 1/(1+exp(β))) / (1/(1+exp(β*(α-1)))/(1+exp(β))) In general, the Beta is 10 and the alpha is 0.5, IM give us a simple command "-fx" with default Beta and alpha (...