Search found 12 matches

by Juce
2015-02-05T03:14:43-07:00
Forum: Digital Image Processing
Topic: Audio equalizer for images?
Replies: 14
Views: 31600

Re: Audio equalizer for images?

I did few tests with a raised-cosine filter : http://i.imgur.com/UCppRpv.png A0 = 1.0; f0L = 0.02; f0H = 0.05; A1 = 0.5; f1L = 0.1; f1H = 0.2; A2 = 1.0; http://i.imgur.com/kzZxgSf.jpg A0 = 1.0; f0L = 0.00; f0H = 0.05; A1 = 2.0; f1L = 0.1; f1H = 1.0; A2 = 0.1; http://i.imgur.com/EqzcfYS.jpg A0 = 0.0;...
by Juce
2014-04-01T05:11:33-07:00
Forum: Digital Image Processing
Topic: Better JPEG quantization tables?
Replies: 84
Views: 179117

Re: Better JPEG quantization tables?

Here is my qtable generator: /* Written in 2014 by Jukka Ripatti To the extent possible under law, the author have dedicated all copyright and related and neighboring rights to this software to the public domain worldwide. This software is distributed without any warranty. See http://creativecommons...
by Juce
2013-02-27T19:16:18-07:00
Forum: Digital Image Processing
Topic: Better JPEG quantization tables?
Replies: 84
Views: 179117

Re: Better JPEG quantization tables?

It seems to me that ITU-T.81 Annex K.1 is often misunderstood. Many software (including libjpeg) and hardware using the tables, despite the fact that the standart says "These tables are provided as examples only and are not necessarily suitable for any particular application."
by Juce
2013-02-27T19:06:00-07:00
Forum: Digital Image Processing
Topic: JPEG q-tables, 'quality', and some other image formats
Replies: 12
Views: 26766

Re: JPEG q-tables, 'quality', and some other image formats

xooyoozoo wrote:Edit: Well, I guess I missed the obvious fact that Photoshop automatically uses different quality factors for luma and chroma, and structural similarity completely focuses on luma.
Have you tried to convert images to monochrome before compression?

Code: Select all

convert orginal.png -fx luminance grayscale.png
by Juce
2013-02-22T14:13:01-07:00
Forum: Digital Image Processing
Topic: JPEG q-tables, 'quality', and some other image formats
Replies: 12
Views: 26766

Re: JPEG q-tables, 'quality', and some other image formats

To that end, I whipped up a small comparison using a state-of-the-art perceptual metric, IW-SSIM What program you used for this comparison? This interest me, because it could help in the development of better quantization tables. I tried previously to develop a SSIM optimized quantization table and...
by Juce
2011-12-02T06:51:43-07:00
Forum: Bugs
Topic: stream corrupts files
Replies: 9
Views: 15926

Re: stream corrupts files

Have you tried these in Windows with 32-bit binaries?
by Juce
2011-11-17T08:47:59-07:00
Forum: Bugs
Topic: stream corrupts files
Replies: 9
Views: 15926

Re: stream corrupts files

Tested on another PC (Windows 7) with http://www.imagemagick.org/download/bin ... indows.zip and the same error appears.

Code: Select all

convert images\logo.png image.bmp
works without any errors.

rose: is too small for testing.
by Juce
2011-11-16T12:57:28-07:00
Forum: Bugs
Topic: stream corrupts files
Replies: 9
Views: 15926

Re: stream corrupts files

Sorry. I tested above commands again and corruption does not happened. Maybe this bug is difficult to repeat. This is a easier repeatable example: stream -map rgb -storage-type short images\logo.png - | echo abc abc stream.exe: IDAT: CRC error `images\logo.png' @ error/png.c/MagickPNGErrorHandler/17...
by Juce
2011-11-14T08:33:20-07:00
Forum: Bugs
Topic: stream corrupts files
Replies: 9
Views: 15926

stream corrupts files

It seems that the stream does not properly handle situations where it can not write to a file. stream -map rgb -storage-type char *.sgi - | x264 - -o testi.mkv --demuxer raw --input-csp rgb --input-res 1280x720 --fps 50 --quiet --frames 10 raw [info]: 1280x720p 0:0 @ 50/1 fps (cfr) resize [warning]:...
by Juce
2011-05-01T05:36:41-07:00
Forum: Bugs
Topic: stream makes false errors if pipe does not read data
Replies: 0
Views: 3640

stream makes false errors if pipe does not read data

stream images\logo.png - | dir > file.txt stream: IDAT: CRC error `images\logo.png' @ error/png.c/MagickPNGErrorHandler/1282. stream: Corrupt image `images\logo.png' @ error/png.c/ReadPNGImage/3252. stream: missing an image filename `images\logo.png' @ error/stream.c/StreamImageCommand/762. "stream...
by Juce
2011-03-22T09:32:47-07:00
Forum: Bugs
Topic: -colors does not work with RGBA PNG
Replies: 1
Views: 3913

-colors does not work with RGBA PNG

sphere.png: http://img233.imageshack.us/img233/4008/sphereu.png convert sphere.png -colors 50 spherecolors50.png http://img691.imageshack.us/img691/610/spherecolors50.png convert sphere.png PNG8:spherepng8.png http://img833.imageshack.us/img833/6731/spherepng8.png This works: convert sphere.png sphe...