Search found 26 matches

by jcupitt
2017-05-09T01:33:56-07:00
Forum: Developers
Topic: DCM--window center/width via command line
Replies: 1
Views: 6391

Re: DCM--window center/width via command line

Hello, this change is being discussed here:

https://github.com/ImageMagick/ImageMagick/pull/477

If you'd like to follow progress or suggest improvements or do some coding.
by jcupitt
2017-05-06T04:05:10-07:00
Forum: Bugs
Topic: DICOM read is broken for many files with 6.9.x and 7.x
Replies: 5
Views: 5518

Re: DICOM read is broken for many files with 6.9.x and 7.x

It looks like this commit is the cause, not the refactoring I fingered earlier:

https://github.com/ImageMagick/ImageMag ... 4ec0b734dd

"The DICOM reader now handles the rescale intercept and slope." from Nov 2015.

6.9.1-10 works, 6.9.2-10 fails.
by jcupitt
2017-05-06T03:57:37-07:00
Forum: Bugs
Topic: DICOM read is broken for many files with 6.9.x and 7.x
Replies: 5
Views: 5518

Re: DICOM read is broken for many files with 6.9.x and 7.x

Unfortunately, many DICOM images use fractional units, for example here the unit is t0, relaxation time. If I have a ushort image with rescale_slope == 0.1 and I express this as an int image, I'm immediately losing 10x of my precision. I think if you bake rescale_slope into the image, you must outpu...
by jcupitt
2017-05-06T02:16:21-07:00
Forum: Bugs
Topic: DICOM read is broken for many files with 6.9.x and 7.x
Replies: 5
Views: 5518

Re: DICOM read is broken for many files with 6.9.x and 7.x

I could have a go at preparing a patch.

I propose simply not interpreting the scale and intercept. Does that sound acceptable?
by jcupitt
2017-05-06T02:09:25-07:00
Forum: Bugs
Topic: DICOM read is broken for many files with 6.9.x and 7.x
Replies: 5
Views: 5518

DICOM read is broken for many files with 6.9.x and 7.x

Hi, it looks like the refactoring of dcm pixel reads last year has broken dicom read for many files. Here's a sample image: http://www.rollthepotato.net/~john/MRIm5.dcm It's a 16-bit, one channel MRI Image. You are welcome to use the image in a test suite. If I examine it with ImageMagick-6.9.8-4 (t...
by jcupitt
2016-10-27T05:30:22-07:00
Forum: Bugs
Topic: error in docs for Sigmoidal Non-linearity Contrast
Replies: 0
Views: 5687

error in docs for Sigmoidal Non-linearity Contrast

Hi, there's a small error in the equation given here: http://www.imagemagick.org/Usage/color_mods/#sigmoidal It reads: ( 1/(1+exp(β*(α-u))) - 1/(1+exp(β)) ) / ( 1/(1+exp(β*(α-1))) - 1/(1+exp(β*α)) ) It should be: ( 1/(1+exp(β*(α-u))) - 1/(1+exp(β*α)) ) / ( 1/(1+exp(β*(α-1))) - 1/(1+exp(β*α)) ) ie. t...
by jcupitt
2016-08-04T04:48:03-07:00
Forum: Developers
Topic: imagemagick7: bug in dicom reader?
Replies: 1
Views: 2997

Re: imagemagick7: bug in dicom reader?

I had a quick look at dcm.c and I don't think it'll ever support Ping properly.

Please ignore this thread.
by jcupitt
2016-07-29T05:31:18-07:00
Forum: Developers
Topic: imagemagick7: bug in dicom reader?
Replies: 1
Views: 2997

imagemagick7: bug in dicom reader?

Hi, I'm updating my image read class to work with im7 and I think I might have found a bug in the dicom reader. This is in 7.0.2-5. Here is a 128x128 unsigned 16-bit image (a slice from a PET scan): https://github.com/jcupitt/libvips/blob/add-magick7/test/images/dicom_test_image.dcm If I PingImage()...
by jcupitt
2016-07-09T07:50:27-07:00
Forum: Developers
Topic: imagemagick7, MagickCore: GetPixelChannels(image) not valid after PingImage()?
Replies: 6
Views: 5799

Re: imagemagick7, MagickCore: GetPixelChannels(image) not valid after PingImage()?

I've found a case when this fails. If I PingImage()/InitializePixelChannelMap(image) on a PDF I see: image->depth = 16 GetImageType() = 6 GetPixelChannels() = 3 But if I ReadImage() the same file I see: image->depth = 16 GetImageType() = 7 GetPixelChannels() = 4 I'd obviously like Ping and Read to r...
by jcupitt
2016-07-09T04:57:30-07:00
Forum: Developers
Topic: imagemagick7, MagickCore: GetPixelChannels(image) not valid after PingImage()?
Replies: 6
Views: 5799

Re: imagemagick7, MagickCore: GetPixelChannels(image) not valid after PingImage()?

It works! And it makes PingBlob() work too.

Thank you very much. I have another question, I'll start a fresh topic.
by jcupitt
2016-07-08T07:55:34-07:00
Forum: Developers
Topic: imagemagick7, MagickCore: GetPixelChannels(image) not valid after PingImage()?
Replies: 6
Views: 5799

imagemagick7, MagickCore: GetPixelChannels(image) not valid after PingImage()?

Hi all, I'm rewriting an import class for imagemagick7, lots of nice improvements, thank you. I'd like to be able to call PingImage() and then get the number of channels with GetPixelChannels(image), but this seems to return 0, at least for JPEG images. It seems I can only use GetPixelChannels() aft...
by jcupitt
2015-11-06T06:15:34-07:00
Forum: Bugs
Topic: Bug: magickcore programs no longer link since IM 6.9.0
Replies: 5
Views: 5215

Re: Bug: magickcore programs no longer link since IM 6.9.0

I did a little digging, the problem seems to be that the coders are being linked into libMagickCore. When libMagickCore-6.Q16.so is linked, the coders are included, and wmf.c uses functions like DrawPathFinish(), which are part of Wand, not Core. Therefore MagickCore programs will not link with defa...
by jcupitt
2015-11-05T02:10:39-07:00
Forum: Bugs
Topic: Bug: magickcore programs no longer link since IM 6.9.0
Replies: 5
Views: 5215

Re: Bug: magickcore programs no longer link since IM 6.9.0

This is with an Ubuntu-installed ImageMagick on the system as well, I don't know if that could be a factor. The system one links fine, it's the 6.9.2 I'm trying to build for testing that's not linking. I can't easily remove the system one without breaking a lot of stuff, but I did try hiding the Ima...