Search found 31 matches

by dargaud
2017-01-17T07:46:51-07:00
Forum: Users
Topic: Making a gif by rotating an image
Replies: 6
Views: 13638

Re: Making a gif by rotating an image

Thanks, that's what I was looking for. Although I couldn't get -delay to work in either .gif or .mng output until I saw GeeMack's syntax being "-set delay". In many places of the documentation it's given as -delay (even the man page) and it doesn't work. I'm using version 6.8.9-9 Q16 x86_6...
by dargaud
2017-01-16T08:20:35-07:00
Forum: Users
Topic: Making a gif by rotating an image
Replies: 6
Views: 13638

Making a gif by rotating an image

Hello all, it's been a while since I last did any 'advanced' IM tricks, so I'm a little rusty. I'd like to take an image and make a gif (or any video format with settable speed and looping) with that image, then that same image rotated by 360*1/n, that same image rotated by 360*2/n, ... that same im...
by dargaud
2014-07-25T07:21:48-07:00
Forum: Users
Topic: Get position of min luminosity along a line
Replies: 3
Views: 3842

Re: Get position of min luminosity along a line

Thanks for the ideas. I don't actually have a sample image yet ! I'm waiting to get one (it'll be a webcam image of a dial, and I need to find the position of the needle, a call to DePolar does the 1st part of the trick).
by dargaud
2014-07-24T00:37:34-07:00
Forum: Users
Topic: Get position of min luminosity along a line
Replies: 3
Views: 3842

Get position of min luminosity along a line

Hello all, Say I have two points. Along the line between them most pixels are white but at a certain point there's a dark patch. How can I get the position of the peak of this dark patch ? Either in cartesian coordinates or expressed as a % along the segment. All I can think of is to get many pixel ...
by dargaud
2014-07-21T09:14:36-07:00
Forum: Users
Topic: Tiling the plane with a single small image (montage)
Replies: 3
Views: 4156

Re: Tiling the plane with a single small image (montage)

THanks. I'd indeed searched for the word 'tile' in the documentation and found "-tile", but not "tile:"
by dargaud
2014-07-21T07:05:06-07:00
Forum: Users
Topic: Tiling the plane with a single small image (montage)
Replies: 3
Views: 4156

Tiling the plane with a single small image (montage)

Hello all, I'm trying to do something simple: tile a large area with a small image. The following command works for putting together 128x128 tiny 2x2 images in a 256x256 square: NB=128; time montage -tile $NBx$NB $( for (( c=1; c<=$((NB*NB)); c++)) ; do echo "Tiny.png" ; done ) -geometry 2...
by dargaud
2012-12-21T06:40:31-07:00
Forum: Users
Topic: Doing an image popup from a script
Replies: 3
Views: 6808

Re: Doing an image popup from a script

Thanks. I'd been thinking along that, but the focus changes are annoying. Someone suggested a great method using zenity here.
by dargaud
2012-12-19T03:59:38-07:00
Forum: Users
Topic: Doing an image popup from a script
Replies: 3
Views: 6808

Doing an image popup from a script

Hello all, I know how I can use "display" to show an image, but I'd like to do something a little more advanced and ask the user a question, like "Is this the right image?" and get a Y/N answer. All this from a shell script. I don't see any direct way to do this in IM without a l...
by dargaud
2012-12-04T23:53:44-07:00
Forum: Users
Topic: mogrify: unable to open image
Replies: 2
Views: 7258

Re: mogrify: unable to open image

Sorry, it was a stupid permission problem. And yes, --verbose works with mogrify.
by dargaud
2012-12-04T12:34:50-07:00
Forum: Users
Topic: mogrify: unable to open image
Replies: 2
Views: 7258

mogrify: unable to open image

Hello all, I have IM running in various scripts on my Ubuntu machine and no problem. But I just tried a batch monochrome convertion and it failed: $ mogrify -verbose -monochrome 20121130-123349-00.jpg 20121130-123349-00.jpg JPEG 640x480 640x480+0+0 8-bit DirectClass 30.2KB 0.020u 0:00.019 20121130-1...
by dargaud
2010-05-14T14:24:49-07:00
Forum: Users
Topic: Telling the difference between color and grayscale image
Replies: 31
Views: 48616

Re: Telling the difference between color and grayscale image

JPEG images may never be pure-greyscale!!!! Yes, that is true. I tested it on a couple thousand BW images from various sources. Obviously, single channel JPG images always have less than 256 colors. 3-channel JPGs from pure greyscale can have up to about a thousand colors in my tests. The reasons c...
by dargaud
2010-05-12T15:55:42-07:00
Forum: Users
Topic: Telling the difference between color and grayscale image
Replies: 31
Views: 48616

Re: Telling the difference between color and grayscale image

You are right, your convert logo: -format "%k" info: works very well in my case.
Thanks
by dargaud
2010-05-12T03:08:54-07:00
Forum: Users
Topic: Telling the difference between color and grayscale image
Replies: 31
Views: 48616

Re: Telling the difference between color and grayscale image

Thanks guys, 'format' was not what I was looking for, I should have mentioned that all images are jpg. The 'image sorting' usage info, now that's it. Why not just do a convert -scale 1x1 and see if all 3 channels are identical ? Risk of false positive ? The section about linear color seems to be exa...
by dargaud
2010-05-11T14:23:30-07:00
Forum: Users
Topic: Telling the difference between color and grayscale image
Replies: 31
Views: 48616

Telling the difference between color and grayscale image

Hello all, I read about this recently in some IM FAQ, but tonight my google-fu must be out for a drink because I can't find the relevant info. I would like a simple way to tell if an image is grayscale or color. Bonus points if it can tell the difference between 2-color B&W, grayscale, sepia, co...
by dargaud
2009-11-17T03:23:43-07:00
Forum: Users
Topic: Identify avi resolution
Replies: 0
Views: 3398

Identify avi resolution

Hello all, I thought that using "identify file.avi" or "identify file.avi[1]" would return (among other things) the X/Y dimensions of the video. But when I type it on my Ubuntu system, all I get is the following message and then the command hangs. mplayer: could not connect to so...