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Still having problems with gray 10bit DPX images

Posted: 2010-02-28T12:15:06-07:00
by aberkl
Hi all,

following my post viewtopic.php?f=3&t=15613 I tried the latest version ImageMagick 6.6.0-0 2010-02-22 Q16

Forcing a 10bit DPX type TrueColor still is not successful, image is of type Grayscale, not TrueColor:

Code: Select all

convert -type TrueColor -depth 10 -size 20x10 xc:gray gray10bitTrueColor1.dpx
identify shows

Code: Select all

Image: gray10bitTrueColor.dpx
...
  Type: Grayscale
  Base type: Grayscale
  Endianess: MSB
  Colorspace: RGB
  Depth: 10-bit
  Channel depth:
    gray: 10-bit
  Channel statistics:
    Gray:
      min: 505 (0.493645)
      max: 38848 (0.493645)
      mean: 505.484 (0.493645)
Also the channel statistics are a bit odd: min and mean are shown on a 10bit base (why is mean a tiny bit larger than min?) whereas max is shown as a 16bit value.

DPXRead (http://media.panavision.com/html/ADI/dpx.htm) tells me in the header view that the gray imageĀ“s Elem(0) descriptor is 6 (Luminance Y) and for a Truecolor image 50 (R,G,B), see http://www.cineon.com/ff_draft.php#tab1 for descriptor values and their meanings.

Best, Andreas

Re: Still having problems with gray 10bit DPX images

Posted: 2010-02-28T12:54:11-07:00
by magick
The Windows release is missing the statistics patch. In the source release of ImageMagick 6.6.0-0 it reports the correct results:
  • Channel statistics:
    Gray:
    min: 505 (0.493645)
    max: 505 (0.493645)
    mean: 505.484 (0.493645)
    standard deviation: 0 (0)
    kurtosis: 0
    skewness: 0
We added a patch to ImageMagick 6.6.0-1 Beta to only set the image descriptor to Luma if the image is grayscale and the image type is not set to TrueColor. 6.6.0-1 Beta will be available sometime tomorrow.

Thanks for the problem report.

Re: Still having problems with gray 10bit DPX images

Posted: 2010-03-05T09:58:41-07:00
by aberkl
Looks like the latest binary for Windows ImageMagick 6.6.0-1 2010-03-03 has fixed both problems.

Thanks and best, Andreas