Search found 16 matches

by tresorjoe
2019-12-06T01:03:05-07:00
Forum: Users
Topic: Return histogram of image with pixel area 3x3 (4x4, 5x5, etc.)
Replies: 5
Views: 2515

Re: Return histogram of image with pixel area 3x3 (4x4, 5x5, etc.)

Hello, I've used RMS to return the color values directly (not the deviation value which is 0,0,0 for zero deviation). The idea is to get information of a "new" histogram which prefers pixels of same colors within a certain neighborhood area (e.g. 3x3, 4x4, 5x5, etc.). In that sense the "new" histogr...
by tresorjoe
2019-12-05T01:45:03-07:00
Forum: Users
Topic: Return histogram of image with pixel area 3x3 (4x4, 5x5, etc.)
Replies: 5
Views: 2515

Re: Return histogram of image with pixel area 3x3 (4x4, 5x5, etc.)

Hello, thanks for your answers. I have tried -statistic with standard-deviation (or better: RMS). Unfortunately with larger files (I tried one with 5000x5000px) the computation is extremely slow and the output text file is understandably extremely large - I got 1.3GB text file which will be impossib...
by tresorjoe
2019-12-04T07:27:18-07:00
Forum: Users
Topic: Return histogram of image with pixel area 3x3 (4x4, 5x5, etc.)
Replies: 5
Views: 2515

Return histogram of image with pixel area 3x3 (4x4, 5x5, etc.)

Hello, I think I understand how histogram works. It returns the color values of an image (e.g. RGB) and the amount of pixels of the same color value in the whole image. So far so good. Is there a way one could look up e.g. a 3x3 pixels area of the SAME color value and return only information of colo...
by tresorjoe
2019-03-26T08:37:14-07:00
Forum: Users
Topic: Shepards distort performance improvement?
Replies: 3
Views: 2536

Re: Shepards distort performance improvement?

That makes sense, thanks for the info. There are 7 control points in Shepards distortion, where the 4 corner points are fixed (input = output) and 3 points are moved (left-center, center-center, right-center). I think I need all of these 7 points to obtain the distortion that I need. Further ideas? ...
by tresorjoe
2019-03-26T08:06:32-07:00
Forum: Users
Topic: Shepards distort performance improvement?
Replies: 3
Views: 2536

Shepards distort performance improvement?

Hello, I am facing performance issues on large RGB files (example 20000px by 12000px). The Shepards distort takes >30 minutes to process such kind of files. I have tried with TIF format (with and without LZW compression) as well as PSD file format. Also tried Q8 version of ImageMagick but the improv...
by tresorjoe
2019-03-06T00:28:57-07:00
Forum: Users
Topic: Free transform / Warp (Photoshop alternative)
Replies: 5
Views: 3555

Re: Free transform / Warp (Photoshop alternative)

sorry, couldn't make it work at all using -distort Perspective. Somehow it doesn't keep the corner points and the desired effect (warp curve) isn't applied. Can you provide me an example command to get something similar as in my previous post where Shepards and Photoshop Warp are compared? Many than...
by tresorjoe
2019-03-04T02:55:18-07:00
Forum: Users
Topic: Free transform / Warp (Photoshop alternative)
Replies: 5
Views: 3555

Re: Free transform / Warp (Photoshop alternative)

I am actually comparing it to Photoshop's Free Transform option using the "Warp" button. Here's what ImageMagick would deliver if I did a centric Shepards move with 4 fixed points (corners) and 3 move points (center-left, center-center, center-right): https://www.dropbox.com/s/l9bs03bua1yu9e0/IM_exa...
by tresorjoe
2019-03-01T00:49:43-07:00
Forum: Users
Topic: Free transform / Warp (Photoshop alternative)
Replies: 5
Views: 3555

Free transform / Warp (Photoshop alternative)

Hello, Tried to use the -distort function with Shepards (taffy-like) approach to move the area around certain control points. As per Shepards and as perfectly explained in the examples section, the transformation does "...it a bit like those 'pins' at the control points are not actually round pins, ...
by tresorjoe
2019-02-28T23:49:58-07:00
Forum: Users
Topic: Convert RGB Tif (black & white pixels only)
Replies: 2
Views: 2299

Re: Convert RGB Tif (black & white pixels only)

Great, worked fine. Thanks. Even preserved the embedded ICC profile.
by tresorjoe
2019-02-28T05:36:04-07:00
Forum: Users
Topic: Convert RGB Tif (black & white pixels only)
Replies: 2
Views: 2299

Convert RGB Tif (black & white pixels only)

Hi, I created a 2 pixel file in RGB, 8bit, TIFF format, sRGB ICC profile embedded, with one pixel being RGB 0,0,0 and the other one RGB 255,255,255. If I use following command the resulting output TIF file is converted to Grayscale: convert RGB-black-and-white-pixel.tif RGB-black-and-white-pixel_out...
by tresorjoe
2018-05-30T09:10:43-07:00
Forum: Users
Topic: Converting a gradient RGB to indexed file
Replies: 3
Views: 3026

Re: Converting a gradient RGB to indexed file

Thanks, snibgo
Didn't know that
"-colors N" guarantees the result will have no more than N colours, but it does NOT guarantee any particular minimum.
Your loop process sounds like a good idea.
by tresorjoe
2018-05-30T08:21:23-07:00
Forum: Users
Topic: Converting a gradient RGB to indexed file
Replies: 3
Views: 3026

Converting a gradient RGB to indexed file

Hello, I encounter an issue when trying to index a gradient file in RGB 8bit with following command line: convert -verbose Gradient.tif -dither none -colors 21 Gradient.png I get the verbose information that the resulting png file only contains 16 colors, not 21 as specified. If I use a larger numbe...
by tresorjoe
2018-04-12T08:20:35-07:00
Forum: Users
Topic: Output colormap to text (not histogram)
Replies: 6
Views: 3192

Re: Output colormap to text (not histogram)

Resolved myself using the grep command: magick -verbose image.png info:- | grep -A 10 -i colormap: > image.txt This just extracts the 10 lines after the colormap entry in the info sequence. Unless anyone has a more elegant solution that dynamically extracts the colormap information only indpendently...
by tresorjoe
2018-04-12T05:13:01-07:00
Forum: Users
Topic: Output colormap to text (not histogram)
Replies: 6
Views: 3192

Re: Output colormap to text (not histogram)

Thanks! That almost does what I need. magick r.png -colors 16 -verbose info:r.txt ...exports a text file including all the image information as obtained with the identify -verbose command. How can I reduce this information to contain only the section within your "code" example? I probably didn't und...
by tresorjoe
2018-04-12T03:03:03-07:00
Forum: Users
Topic: Output colormap to text (not histogram)
Replies: 6
Views: 3192

Re: Output colormap to text (not histogram)

I always get the histogram list instead of the colormap list (see above). How can I extract this section from -verbose and write it into a text file?: Colormap: 0: (133,114,144,255) #857290FF srgba(133,114,144,1) 1: ( 80, 67, 80,255) #504350FF srgba(80,67,80,1) 2: (152,144,175,255) #9890AFFF srgba(1...