Legacy ImageMagick Discussions Archive

Your sigmoidal-contrast first value 0.45 is so small as to be hardly doing anything, if I am not mistaken. It is nearly a linear function with slope almost zero, thus an no-op situation. What do you get if you remove the -sigmoidal-contrast on both sides? Is it at all visually different? What is th...

what does bam mean? BAM are my initials :) Default https://dl.dropbox.com/u/106615031/dsp/imagemagick/bamscaler/dcpfever/775_1344831871921.jpg-default.jpg Latest BAM Scaler revision https://dl.dropbox.com/u/106615031/dsp/imagemagick/bamscaler/dcpfever/775_1344831871921.jpg-bamscaler.jpg #!/bin/bash...

Yes. Post a name for the filter and we'll code it up in IMv7 Alpha. If it proves useful, we can backport it to IMv6. I'd like the name to be bam or bamscaler . Thanks guys I appreciate all your critique and support! :) EDIT It seems my filter is very similar to Nicolas' "scheme of the day"...

Could it possibly be turned into an ImageMagick filter?

@NicolasRobidoux I think I might have found satisfactory settings. :) Triangle https://dl.dropbox.com/u/106615031/dsp/imagemagick/supersampled%20sigmoidized%20catmull-rom/skull_1333p_triangle.png BAM Scaler https://dl.dropbox.com/u/106615031/dsp/imagemagick/supersampled%20sigmoidized%20catmull-rom/s...

@NicolasRobidoux The latest version of my filter uses direct resampling as opposed to "supersampling". convert new.png -define filter:kaiser-beta=4 -define filter:window=kaiser -filter sinc -colorspace rgb -sigmoidal-contrast 1.25x10% -distort resize 1333% -colorspace srgb +repage -samplin...

just curious but why 1) are you using -sample and -resize? -sample just magnifies by duplicating pixels (not interpolating them) and -resize 100% is a no-op (in principle and depending upon the filter how good it is at that). To be honest, I do not know if all the filter controls work on -sample an...

@NicolasRobidoux I compared a standard Jinc resize to my version using a convolution and sigmoidal contrast and I believe the results show promise. Jinc Resize https://dl.dropbox.com/u/106615031/dsp/imagemagick/supersampled%20sigmoidized%20catmull-rom/rose_jinc-resize.png convert rose: -filter jinc ...

@NicolasRobidoux I increased the C parameter on the filter so that it's now an overly sharp Catmull-Rom. https://dl.dropbox.com/u/106615031/dsp/imagemagick/example2/new_cubic-b0c1-10x-convolution_gamma-correct_less-safe-sigmoidal-11p6933.png convert new.png -define filter:blur=10 -define filter:b=0 ...

https://dl.dropbox.com/u/106615031/dsp/imagemagick/example3/rose-catrom_10x-convolution_gamma-correct_less-safe-sigmoidal-11p6933.png https://dl.dropbox.com/u/106615031/dsp/imagemagick/example2/new_catrom_10x-convolution_gamma-correct_less-safe-sigmoidal-11p6933.png convert rose: -define filter:blu...

I guess what I should ask is if the direct resampling or the convolution is a more accurate representation of how the final image should look.

I suggest you get your math background built up a bit by taking algebra courses at a minimum. Then take a few computer courses so you know the basics of computer processing, coding, computer graphics and image processing. Some or all of these can you do by buying the right books and reading on your...

original https://dl.dropbox.com/u/106615031/dsp/imagemagick/example2/new.png zero order hold https://dl.dropbox.com/u/106615031/dsp/imagemagick/example2/zoh10x.png direct resampling https://dl.dropbox.com/u/106615031/dsp/imagemagick/example2/triangleresize10x.png zoh + convolution https://dl.dropbo...

I want to pursue an education in the types of things covered on this forum. I admire all of you for all the hard work and effort you've put into all of this and I want to be able to help out. My problem is that I have an 8th grade math level and a GED. I live in Kentucky and I would most likely go t...

Thanks anthony, that does exactly what I need.