Search found 30 matches

by user001
2017-09-12T18:44:16-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

Thanks, what is divide.pfm by the way?
by user001
2017-09-12T17:29:10-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

Thanks for the info, fmw42. It seems that I am still able to write 64-bit tiff output using Q16+HDRI IM:
$ identify quotient.tif
quotient.tif TIFF 64x64 64x64+0+0 64-bit Grayscale Gray 33.1KB 0.000u 0:00.000
by user001
2017-09-12T17:19:36-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

Thanks, magick. I did try using the default quantum but I still have the same autoconf error. Would you know how to find the most recent version of IM that is compatible with my version of autoconf? Perhaps I should just try v6.7.2-7, since that is the version already available on the system on whic...
by user001
2017-09-12T17:14:23-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

Same problem with IM v6.9.9. Any ideas?
by user001
2017-09-12T16:54:26-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

When I try to install (`./configure --prefix=/home/<username>/imq64 --with-quantum-depth=64 --enable-hdri && make && make install`), I get the following warning; this is being done on a CentOS v6.9 system. CDPATH="${ZSH_VERSION+.}:" && cd . && /bin/sh /home/<username>/imq64/ImageMagick/config/missin...
by user001
2017-09-12T15:54:57-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

It seems that I'll need to make a custom ImageMagick build. I just found a couple pages on this (https://www.imagemagick.org/script/install-source.php, https://www.imagemagick.org/script/advanced-unix-installation.php), which I will read. From a cursory glance, it seems that I will need something li...
by user001
2017-09-12T15:43:22-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

Note that since the differences between the two quotients are both positive and negative, the mean is fairly similar: >> format long g >> mean2(Q(:)) % 4.09287688023606 [the ImageMagick result] >> mean2(q(:)) % 4.09287688706628 [the Matlab result] I would be interested to know if the operation could...
by user001
2017-09-12T15:36:26-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

Re: floating-point, pixel-wise image division

Good point. I tried the command on two different systems: One had the following version: Version: ImageMagick 6.7.2-7 2017-03-22 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2011 ImageMagick Studio LLC Features: OpenMP The second was: Version: ImageMagick 7.0.4-4 Q16 x86_64 2017-01-2...
by user001
2017-09-12T14:41:06-07:00
Forum: Users
Topic: floating-point, pixel-wise image division
Replies: 15
Views: 6576

floating-point, pixel-wise image division

I am trying to port a simple image division function from Matlab to ImageMagick, but the results are different in the two languages. I believe the discrepancy is too great to be simply a consequence of floating point error and instead insinuates some mistake in my ImageMagick syntax. Assume two gray...
by user001
2017-09-05T09:44:41-07:00
Forum: Users
Topic: normalizing mean intensities (grayscale)
Replies: 5
Views: 2713

Re: normalizing mean intensities (grayscale)

Thanks, that works. I'm apparently still in the habit of using the old IM commands (convert, identify, display, montage, etc.). I noticed that `-format "%[fx:mean]"` gives the mean intensity normalized to 1 (i.e., divided by 65535 for 16-bit or 255 for 8-bit images), whereas `-format "%[mean]"` give...
by user001
2017-09-05T09:00:55-07:00
Forum: Users
Topic: normalizing mean intensities (grayscale)
Replies: 5
Views: 2713

Re: normalizing mean intensities (grayscale)

Thanks for your help. One image will be a constant and I will be looping over a set of images, setting their mean equal to that of a reference image, so I think your second example is most germane to what I am trying to do. Could you please tell me how %NEW_MEAN% could be introduced as a shell varia...
by user001
2017-09-04T19:30:45-07:00
Forum: Users
Topic: normalizing mean intensities (grayscale)
Replies: 5
Views: 2713

normalizing mean intensities (grayscale)

I have two 16-bit, grayscale images, img1 and img2 and would like to equalize their intensities such that the mean pixel value of each image is the same. In Matlab, I would do this as follows: img1 = im2double(imread('img1.tif')); img2 = im2double(imread('img2.tif')); img2_eq = im2uint16( img2 ./ me...
by user001
2015-11-02T03:37:39-07:00
Forum: Users
Topic: overlaying a canvas on an image
Replies: 4
Views: 1582

Re: overlaying a canvas on an image

Oh, indeed! I just checked my terminal emulator history and found that I made the same mistake (trying to use the syntax "-geometry X%xY% -crop" instead of "-crop X%xY%"). A regrettable error, for the resolution of which I convey my sincerest thanks.
by user001
2015-11-02T02:40:17-07:00
Forum: Users
Topic: overlaying a canvas on an image
Replies: 4
Views: 1582

Re: overlaying a canvas on an image

Apologies, it was supposed to be "crop." I edited the post to make this correction.
by user001
2015-11-02T01:25:46-07:00
Forum: Users
Topic: overlaying a canvas on an image
Replies: 4
Views: 1582

overlaying a canvas on an image

I am trying to overlay a canvas (specifically a white rectangle of defined size) on an image. The following command, which I expect to overlay a rectangle of 100 pixel width and 4 pixel height, does not overlay a rectangle of the expected size: convert file.tif -gravity center -crop 50%x50% 'xc:whit...