Search found 12908 matches

by snibgo
2013-02-03T02:50:54-07:00
Forum: Users
Topic: Reduce color depth and dither?
Replies: 5
Views: 9058

Re: Reduce color depth and dither?

Ah, sorry. "-remap" can dither, and can use the colours from your Sample2:

Code: Select all

convert Sample.png -depth 4 Sample2.png 
convert Sample.png -remap Sample2.png Sample3.png
Is Sample3.png what you want?
by snibgo
2013-02-03T02:38:06-07:00
Forum: Developers
Topic: MagickWand writes a bitmap incompatible with Win32 LoadImage
Replies: 3
Views: 6845

Re: MagickWand writes a bitmap incompatible with Win32 LoadI

This may be a problem with DIB headers. These come in different flavours: seven, at the last count. See http://en.wikipedia.org/wiki/BMP_file_format If I understand correctly (and I probably don't), IM understands three of them; see "convert -list format". Maybe your program implicitly expects one f...
by snibgo
2013-02-02T20:24:47-07:00
Forum: Users
Topic: Grayscale matters
Replies: 7
Views: 5455

Re: Grayscale matters

For PDFs that are a single raster image in a vector wrapper, as this one is, I open it in Adobe Reader and control-C the image, which copies it to the clipboard. Then ... convert clipboard: info: ... tells me how many pixels it has. Then I try a simple convert (at 72 ppi)... convert test.pdf info: ....
by snibgo
2013-02-02T19:48:13-07:00
Forum: Users
Topic: Grayscale matters
Replies: 7
Views: 5455

Re: Colorizing scanned grayscale PDF

I cross-posted with fmw42. His "+level colors" is far more elegant, and probably quicker, than my version that messes around with alpha. My "-density 150" is what you need for readable text.
by snibgo
2013-02-02T19:37:08-07:00
Forum: Users
Topic: Grayscale matters
Replies: 7
Views: 5455

Re: Colorizing scanned grayscale PDF

For example, green text on a white background: convert -density 150 test.pdf lecture2.png convert lecture2.png -alpha Copy -fuzz 100% -fill White -opaque Gray -background Green -alpha Remove lecture3.png convert lecture3.png lecture3.pdf I've shown it as three stages, but you could combine them into...
by snibgo
2013-02-02T18:46:13-07:00
Forum: Users
Topic: A More Formal Description of the ImageMagick Machine
Replies: 12
Views: 9404

Re: A More Formal Description of the ImageMagick Machine

A good description. A couple of observations: The IM "convert" language is essentially postfix, although (for historical reasons) many operators can also work in the prefix position. Example: "convert -resize 800% rose: bigrose.png". I expect (and hope) these anomonlies will be phased out. The seque...
by snibgo
2013-02-02T17:40:53-07:00
Forum: Users
Topic: Reduce color depth and dither?
Replies: 5
Views: 9058

Re: Reduce color depth and dither?

convert Sample.png -colors 16 Sample2.png
by snibgo
2013-02-02T10:29:25-07:00
Forum: Users
Topic: Removing Shadow and Background for OCR
Replies: 8
Views: 10072

Re: Removing Shadow and Background for OCR

Get a scanner. Life will be so much easier. If that isn't feasible (perhaps horrible images like this come from clients), use an interactive editor to square up the image, crop it and curve it. Automated processing is possible for this particular image, of course. But a generic solution for dodgy ph...
by snibgo
2013-02-01T19:06:33-07:00
Forum: Bugs
Topic: DXT5 Issues in DDS Format (Windows)
Replies: 9
Views: 16914

Re: DXT5 Issues in DDS Format (Windows)

The source image has gone away. Can you re-post it?
by snibgo
2013-02-01T17:53:57-07:00
Forum: Users
Topic: resized (smaller) image files larger than original?
Replies: 7
Views: 16544

Re: resized (smaller) image files larger than original?

If this is the only re-save you are doing, it shouldn't harm the visual quality much. If you are doing multiple changes and saving as jpeg each time, then you shouldn't. Instead, use a lossless compression for intermediate files. IM can't get a jpeg quality setting from non-jpeg files. I don't know ...
by snibgo
2013-02-01T17:38:47-07:00
Forum: Bugs
Topic: convert tiff to tiff breaks files
Replies: 11
Views: 25067

Re: convert tiff to tiff breaks files

With the usual Windows tools I use ("Explorer" and "Photo Viewer"), Altered.TIF looks fine. However, "Microsoft Office Picture Manager 2006" shows Altered.TIF as green. There is a "color enhancement" facility that lets me click on an area in the picture that should be white. So I do, and the picture...
by snibgo
2013-02-01T10:19:56-07:00
Forum: Bugs
Topic: error in -draw "polyline ..." function
Replies: 5
Views: 4604

Re: error in -draw "polyline ..." function

What do you think it is doing wrong?

It's also helpful if you state your platform and IM version.
by snibgo
2013-02-01T04:14:55-07:00
Forum: Users
Topic: Help with using IM convert
Replies: 3
Views: 4984

Re: Help with using IM convert

I have reported this on the bugs forum: viewtopic.php?f=3&t=22720
by snibgo
2013-02-01T04:14:05-07:00
Forum: Bugs
Topic: Transparency removed
Replies: 7
Views: 14954

Transparency removed

The current version of IM for Windows, 6.8.2-0, seems to be removing transparency. "%IMG682%convert" -size 100x100 xc:none -fill Red -draw "rectangle 20,20 80,80" t.png "%IMG682%convert" t.png t2.png t2.png has black where t.png wa transparent. See also http://www.imagemagick.org/discourse-server/vi...
by snibgo
2013-02-01T04:04:28-07:00
Forum: Users
Topic: Help with using IM convert
Replies: 3
Views: 4984

Re: Help with using IM convert

I can reproduce the problem on Windows 7 in 6.8.2-0. It did not occur in v 6.8.1-10. The problem is independant of "+append". It seems that IM 6.8.2 is simply removing transparency: "%IMG682%convert" -size 100x100 xc:none -fill Red -draw "rectangle 20,20 80,80" t.png "%IMG682%convert" t.png t2.png t...