Search found 8874 matches

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: 27967

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: 493

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: 493

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: 493

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: 493

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: 350

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: 350

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: 493

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: 1750

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: 278

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: 1750

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: 463

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: 1316

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: 928

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: 9847

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.