Search found 8878 matches

by anthony
2017-12-07T17:58:00-07:00
Forum: Users
Topic: why is median of a sequence of images slower than mean
Replies: 13
Views: 390

Re: why is median of a sequence of images slower than mean

I have updated IM Examples, adding a actual example for median
Its not a great example, but it does the job.
http://www.imagemagick.org/Usage/layers ... seq_median
by anthony
2017-12-07T16:23:57-07:00
Forum: Users
Topic: why is median of a sequence of images slower than mean
Replies: 13
Views: 390

Re: why is median of a sequence of images slower than mean

The command line discards the source images, basically as it only has a single image list, so results of a image process replaces the source image list. However the imagemagick library does not have that restriction. The results are returned as a completely separate image list, preserving the source...
by anthony
2017-11-30T16:35:25-07:00
Forum: Users
Topic: why is median of a sequence of images slower than mean
Replies: 13
Views: 390

Re: median of a sequence of images operating pixel-by-pixel

It probably should be using -intensity.

also rather than necro-posting you should have started a new post.
I am splitting the post into a separate topic.
by anthony
2017-11-23T16:34:06-07:00
Forum: MagickWand for PHP
Topic: Transparent colour goes black when png/gif resized and conve
Replies: 11
Views: 28808

Re: Transparent colour goes black when png/gif resized and conve

Better still look at which has a number of different examples of the problem and how to fix it/ IM Usage Examples, Removing Transparency from Images http://www.imagemagick.org/Usage/masking/#remove The section of example immediately above that introduces the -alpha image processing operators. Also t...
by anthony
2017-11-19T18:15:46-07:00
Forum: Users
Topic: Compare -FUZZ <- how it is calculated
Replies: 20
Views: 1368

Re: Compare -FUZZ <- how it is calculated

Hmmm one side effect of -metric PAE. if you compare any image to another that is the same size but all black PAE will get you the largest color value in the image. On the other hand MAE will get you the average of all the color values in the image. Note this is over ALL color channels. A -metric FUZ...
by anthony
2017-11-19T18:05:37-07:00
Forum: Users
Topic: Compare -FUZZ <- how it is calculated
Replies: 20
Views: 1368

Re: Compare -FUZZ <- how it is calculated

If I use an extrememly high fuzz factor of 82% (larger that the .81 value we had before), then black and cyan SHOULD be the same! [b]compare xc:black xc:cyan -metric AE -fuzz 82% null:[/b] 1 As you can see I have the WRONG result! Something is not correct, and I will be report this though it may be...
by anthony
2017-11-16T17:52:16-07:00
Forum: Users
Topic: Compare -FUZZ <- how it is calculated
Replies: 20
Views: 1368

Re: Compare -FUZZ <- how it is calculated

The -metric AE is completely different to PAE. AE only returns a boolean (error or not-error) result, returning total count of the number of different pixels. So normally is ANY pixel is different it is different! [b]compare xc:black xc:cyan -metric AE null:[/b] 1 However AE is one of the few metric...
by anthony
2017-11-13T21:38:34-07:00
Forum: Users
Topic: Compare -FUZZ <- how it is calculated
Replies: 20
Views: 1368

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: 782

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: 782

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: 1368

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: 2409

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: 650

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: 2409

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...