Search found 28 matches

by steve___
2014-08-24T09:16:39-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

I also think that something like this may work well given what you have found to work well, esp. with color: convert \( input.png -depth 16 -set colorspace sRGB -colorspace RGB \) \ \( -clone 0 -gamma 1.666666666666666 -filter RobidouxSharp -distort Resize $res -gamma 0.6 \) \ \( -clone 0 -filter R...
by steve___
2014-08-24T09:14:43-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

Thank you Steve. Putting the result of your testing in my "What worked for someone" memory box. P.S. I persist in thinking that an EWA can always be found that does better than any tensor method in a specific situation. Have you tried something like convert infile[0] -quiet -colorspace RGB -gamma 1...
by steve___
2014-08-24T05:37:48-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

NicolasRobidoux wrote:Steve: I think you forgot to include the originals in your zip file? Or is the orig folder meant to be empty.
Sorry about that. The originals can be found here:
https://dev.zcomix.com/files/convert-orig.zip

I was away yesterday. I have input to your thoughts above. I'll
respond later today.
by steve___
2014-08-21T17:13:30-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

After much testing with ImageMagick 6.8.8-5 HDRI Q16 I've settled on Catrom with a gamma setting of 1.333333333333333/.75 and no ewa. Here is the syntax I'm using: $ convert infile[0] -quiet -colorspace RGB -gamma 1.333333333333333 -filter Catrom -resize $res -gamma .75 -colorspace sRGB +repage outf...
by steve___
2014-08-01T09:27:55-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

I am using: $ convert -version Version: ImageMagick 6.8.7-6 Q16 x86_64 2013-11-17 http://www.imagemagick.org Copyright: Copyright (C) 1999-2013 ImageMagick Studio LLC Features: DPC HDRI Modules OpenCL OpenMP Delegates: bzlib cairo fontconfig freetype gslib jng jp2 jpeg lcms lqr ltdl lzma openexr pan...
by steve___
2014-08-01T08:40:29-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

Using photoshop I created a set of delta images to illustrate how much noise was created after down-sampling. The original, down-sample and delta images can be found here[1]. For the D2 images I upscaled the original file to twice its size, with nearest-neighbor resampling, then upscaled the convert...
by steve___
2014-08-01T07:06:07-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

How do I know which settings to use for GAMMA and RECIPROCAL_OF_GAMMA?

The thin-line artwork is one of 12 images to test, some of the images
have full colour artwork.

I have done some initial tests. I will post the results later.
by steve___
2014-07-30T10:09:52-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

Re: convert - downscaling comic pages

I'd like to take a stab at doing some tests. How do I access the EWA filters? I do not see them in the output of 'convert -list filter'. Before comparing the output, I'd like to get feedback on the syntax I'm using to be sure it's what Nicolas meant above. convert img/bw-thin_line.jpg -colorspace RG...
by steve___
2014-05-24T13:27:17-07:00
Forum: Users
Topic: convert - downscaling comic pages
Replies: 82
Views: 77772

convert - downscaling comic pages

I'll have users uploading jpg's, png's and possibly gif's. If the width is greater than 750px (eg) then I need to resize them. See https://dev.zcomix.com for examples of images I'll be getting. I'd like to keep the image quality high, as well as the logic simple. I would never be upscaling the image...
by steve___
2013-06-21T08:58:22-07:00
Forum: Users
Topic: auto-crop
Replies: 10
Views: 16149

Re: auto-crop

Is there a nice way to get around using -fuzz? I'm concerned the
the percentage I settle on will either be too greedy or too loose.

-steve
by steve___
2013-06-21T08:39:42-07:00
Forum: Users
Topic: auto-crop
Replies: 10
Views: 16149

Re: auto-crop

Wow thanks a lot, it really is appreciated.

-steve
by steve___
2013-06-20T10:38:50-07:00
Forum: Users
Topic: auto-crop
Replies: 10
Views: 16149

auto-crop

I'm building a lightbox. Currently the raw images look similar to this: http://i7.minus.com/jbishR4z6Gj9on.jpg I'm looking to find away to auto crop the photos. Using this command: convert foo.jpg -fuzz 28% -trim +repage foo_crop.jpg I get this result: http://i2.minus.com/jzKZ3hGluvWPL.jpg Is this t...
by steve___
2012-07-17T10:31:48-07:00
Forum: Users
Topic: Upscaling
Replies: 2
Views: 5254

Upscaling

I have images similar to this: http://imgur.com/189v5 Their widths are between 1000px and 1200px. I'd like to upscale them to a width of 1280px. In my first attempt I tried: $ convert -resize 1280 a.jpg b.jpg The picture was slightly blurry. I googled around and came across '-unsharp -30': $ convert...