Search found 8885 matches

by anthony
2017-11-13T21:38:34-07:00
Forum: Users
Topic: Compare -FUZZ <- how it is calculated
Replies: 20
Views: 5616

Re: Compare -FUZZ <- how it is calculated

Internally IM uses its compile time quaility setting. 8 bit images are stored at that quality and then saves at the current image 'depth' whcih is usualy the image input depth. Also HDRI versions of IM store values a floating poitn numbers in memory but use Q16 as a base for those numbers. EG typica...
by anthony
2017-11-12T21:01:58-07:00
Forum: Users
Topic: No consistent effect across different resolutions
Replies: 12
Views: 2239

Re: No consistent effect across different resolutions

Since your 1080 image is larger than your 540 by about 2 in height, have you tried <threshold map="hlines4x2a"> <description>Horizontal Lines 4x2 (bounds adjusted)</description> <levels width="4" height="2" divisor="10"> 3 3 3 3 9 9 9 9 </levels> </threshold> Sorry, I know little about dithering an...
by anthony
2017-11-12T17:59:16-07:00
Forum: Users
Topic: No consistent effect across different resolutions
Replies: 12
Views: 2239

Re: No consistent effect across different resolutions

Dithering is a pixel level process, and as such is dependant of the resolution of the image. There is not a lot you can do about that. Also colors that are being dithered can be effected by the resize operations, becoming smoother at lower resolutions, which makes dither work differently at pixel le...
by anthony
2017-11-12T16:51:14-07:00
Forum: Users
Topic: Compare -FUZZ <- how it is calculated
Replies: 20
Views: 5616

Re: Compare -FUZZ <- how it is calculated

Actually without a percentage Fuzz defines that sphere in terms of pixel value distance. But while Fuzz is a sphere for opaque RGB values it is a lot more complex when transparency is involved. The sphere remains the same but the distance between the pixels gets closer as the pixles become more tran...
by anthony
2017-11-09T16:35:20-07:00
Forum: Users
Topic: How to dirty a font
Replies: 20
Views: 5939

Re: How to dirty a font

opps my bad.. I removed the xc: from the example.. The lightblue did not matter because of the threshold so I removed some of the useless options and went a little too far. Example is now... convert -size 320x100 xc: \ -font Candice -pointsize 72 -annotate +25+65 'Anthony' \ -spread 1 -blur 0x1 -thr...
by anthony
2017-11-08T19:26:23-07:00
Forum: Users
Topic: adding text to just one page of a multiple page TIFF
Replies: 9
Views: 2516

Re: adding text to just one page of a multiple page TIFF

Gif Animation Modifications is a good away to see how to handle multiple pages

http://www.imagemagick.org/Usage/anim_mods/#frame_mod
by anthony
2017-11-08T18:51:52-07:00
Forum: Users
Topic: How to dirty a font
Replies: 20
Views: 5939

Re: How to dirty a font

Added the simpler spread technique to "Compound Fonts" section of IM Examples http://www.imagemagick.org/Usage/fonts/#dirty_print May take a hour or so to appear online. The Compound Fonts Section is one of the oldest of ImageMagick Examples, and basically explores simple techniques of modifying a s...
by anthony
2017-11-08T16:33:43-07:00
Forum: Users
Topic: Cropping unknown amount from left edge to leave a given-width image
Replies: 7
Views: 2673

Re: Cropping unknown amount from left edge to leave a given-width image

The biggest difference between -extent and -crop is that -extent will not only crop an image but expand it to. That is if the image was smaller than 1220 pixels, it will expand the image by 1220 pixels, that is why it needs to 'overlay' the image onto a background. Crop on the other hand will NEVER ...
by anthony
2017-09-27T18:11:13-07:00
Forum: Users
Topic: optimizing 'convert' speed
Replies: 4
Views: 2779

Re: optimizing 'convert' speed

Also using -depth 8 will have no effect on run time. It is only used to specify the output save depth, and that defaults to the images input depth (probably already 8 bit. To get a speed improvement (with a loss in quality though not for this type of command) you want to change the compile time "Qua...
by anthony
2017-09-20T23:30:38-07:00
Forum: Users
Topic: Alternative to "-morphology dilate octagon".
Replies: 11
Views: 2968

Re: Alternative to "-morphology dilate octagon".

Convolve and Simple Morpholgy are essentually applied by the same routines, UNLESS they somehow invooke GPU's to do the function. The simple reason -morpohology dialate:30 octagon is faster than -morpohology dialate octagon:61 is that it applies a vastly smaller kernel 30 times rather than one very ...
by anthony
2017-08-27T17:42:13-07:00
Forum: Users
Topic: Determining if All Pixels Fall Within a Color Range
Replies: 22
Views: 13543

Re: Determining if All Pixels Fall Within a Color Range

An alternative for 3 is to -solarize the image at 50% That make pure white, pure black (folding the colorspace in half) As such is any pixels after a solarize is more than 2% away from black, you have grey pixels.
by anthony
2017-06-20T16:35:12-07:00
Forum: Users
Topic: Identify all colours in picture and output to txt ?
Replies: 22
Views: 8142

Re: Identify all colours in picture and output to txt ?

Extracting image colors... http://www.imagemagick.org/Usage/quantize/#extract Specifically you either use unique colors, or use the histogram: output format and extract teh image comment. convert rose: -format %c -depth 8 histogram:info:- This not only outputs the colors (one color per line), but al...
by anthony
2017-06-20T16:30:06-07:00
Forum: Users
Topic: convert fails for fig to jpg
Replies: 1
Views: 1084

Re: convert fails for fig to jpg

The Fig file format is a vector image format saved by the program "xfig" . This has not seem any real changes for at least 20 years, but is still available using Linux. Heck.. I'm so old I still use it for basic line drawings (even combined with small raster images). The best way to output fig files...
by anthony
2017-05-04T21:40:54-07:00
Forum: Users
Topic: Getting standard Hex colors..
Replies: 18
Views: 33593

Re: Getting standard Hex colors..

If you do not mind a extra comma at the end, and no newline, you can also do something like this...

Code: Select all

convert rose: -colorspace Lab -scale 2x2! -crop 1x1 -format '%[fx:r*100],'  info:-
36.228,51.7021,54.4274,39.9542,
by anthony
2017-04-26T16:21:52-07:00
Forum: Bugs
Topic: IM7.0.5-5 Problem with border and transparent canvas...
Replies: 9
Views: 7145

Re: IM7.0.5-5 Problem with border and transparent canvas...

In the second set of examples of Border... http://www.imagemagick.org/Usage/crop/#border I go though a number of different compose methods, including Copy. And the very next example (third one) that is a specific one for Copy! convert star.gif -bordercolor LimeGreen -compose Copy \ -border 5 star_bo...