16-bit DPX with alpha? How can this be?

[stevepugh]

Hi all,

I'm using convert to read a DPX frame, scale it, blend a 32-bit Targa over it, draw some text, and save it back out as a DPX file. Even though I'm specifying "-depth 10" and even trying to strip out any alpha data with "-channel rgb", I am somehow outputting 16-bpc DPX frames with alpha embedded, or at least identify.exe thinks so! Needless to say, other programs freak out on this alien format as well. This is running on 6.6.9.9-Q16.

Here is my 'identify -verbose" output"

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  Format: DPX (SMPTE 268M-2003 (DPX 2.0))
  Class: DirectClass
  Geometry: 2048x1168+0+0
  Resolution: 72x72
  Print size: 28.4444x16.2222
  Units: Undefined
  Type: TrueColorMatte
  Base type: TrueColor
  Endianess: MSB
  Colorspace: RGB
  Depth: 10/16-bit
  Channel depth:
    red: 16-bit
    green: 16-bit
    blue: 16-bit
    alpha: 16-bit
  Channel statistics:
    Red:
      min: 0 (0)
      max: 1023 (0.999039)
      mean: 144.267 (0.140888)
      standard deviation: 107.629 (0.105108)
      kurtosis: 21.3653
      skewness: 3.80073
    Green:
      min: 0 (0)
      max: 1023 (0.999039)
      mean: 88.8943 (0.0868122)
      standard deviation: 105.165 (0.102702)
      kurtosis: 33.2795
      skewness: 5.32321
    Blue:
      min: 0 (0)
      max: 1023 (0.999039)
      mean: 68.5614 (0.0669556)
      standard deviation: 105.852 (0.103373)
      kurtosis: 36.4368
      skewness: 5.71321
    Alpha:
      min: 0 (0)
      max: 1023 (0.999039)
      mean: 1022.5 (0.998551)
      standard deviation: 22.5998 (0.0220705)
      kurtosis: 2043
      skewness: 45.2217
  Image statistics:
    Overall:
      min: 0 (0)
      max: 1024 (1)
      mean: 75.8017 (0.0740262)
      standard deviation: 92.6812 (0.0905103)
      kurtosis: 47.3923
      skewness: 6.46798
  Alpha: rgba(99.9039%,99.9039%,0%,0)   #FFC0FFC000000000
  Rendering intent: Undefined
  Interlace: None
  Background color: white
  Border color: rgba(223,223,223,1)
  Matte color: grey74
  Transparent color: none
  Compose: Over
  Page geometry: 2048x1168+0+0
  Dispose: Undefined
  Iterations: 0
  Compression: Undefined
  Orientation: TopLeft
  Properties:
    date:create: 2011-05-18T14:50:37-07:00
    date:modify: 2011-05-18T14:54:09-07:00
    dpx:file.creator: ImageMagick 6.6.9-9 2011-05-10 Q16 http://www.imagemagick.org
    dpx:file.ditto.key: 1
    dpx:file.timestamp: 2011-05-18T14:53:19-07:
    dpx:file.version: V2.0
    dpx:film.frame_position: 0
    dpx:film.held_count: 0
    dpx:film.sequence_extent: 0
    dpx:image.orientation: 0
    dpx:orientation.aspect_ratio: 0x0
    dpx:orientation.border: 0x0+0+0
    dpx:orientation.x_offset: 0
    dpx:orientation.x_size: 0
    dpx:orientation.y_offset: 0
    dpx:orientation.y_size: 0
    dpx:television.time.code: 00:00:00:00
    dpx:television.user.bits: 00:00:00:00
    signature: cead80091a236e98cdf0b31f5d84a51791c44dfaacbffd9a3c09f8fb0db9bbfb
    software: ImageMagick 6.6.9-9 2011-05-10 Q16 http://www.imagemagick.org
  Artifacts:
    verbose: true
  Tainted: False
  Filesize: 12.77MBB
  Number pixels: 2.392MB
  Pixels per second: 23.45MB
  User time: 0.078u
  Elapsed time: 0:01.101
  Version: ImageMagick 6.6.5-3 2010-10-22 Q16 http://www.imagemagick.org

And here are the command lines I'm using - it's a two-step process because I haven't had the strength to in-line the first resize operation (that'll come next). I had some issues with an unexpected source frame size yesterday and started making changes to accomodate it, and before I could say "work slowly and incrementally", the wheels had fallen off the bus and I've got alpha channels in every single frame I create no matter how I try to avoid them. Weird, right? Can any kind souls shed any light on my woe? It's makin' me cah-raaayzee!

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S:\2d\ImageMagik\ImageMagick\imconvert.exe "Z:\Test\shots\CF_124_010\composites\CF_124_010_v02_cc\2048x1168\CF_124_010_comp_v02.0026.dpx" -resize 1920x1080 -channel rgb -normalize -flatten c:\tmpslate.tga

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S:\2d\ImageMagik\ImageMagick\imconvert.exe -composite -gravity center "c:\tmpslate.tga" "S:\_Degobah4.0\Images\Slates\GenericSlate_R05.0001.tga" -depth 8 -fill WHITE -font "c:\WINDOWS\Fonts\HelveticaNeueLTCom-Md.ttf" -pointsize 20 -gravity northwest -draw "text 582,373 'PROJECT'" -fill WHITE -pointsize 40 -gravity northwest -draw "text 690,370 'Test '" -pointsize 20 -gravity northwest -draw "text 582,430 'SCENE'" -fill WHITE -pointsize 40 -gravity northwest -draw "text 690,428 'CF_124_010 v02'" -font "C:\WINDOWS\Fonts\HelveticaNeueLTCom-Md.ttf" -fill WHITE -pointsize 20 -gravity northwest -draw "text 582,487 'LENGTH'" -fill "rgb(124,124,124)" -pointsize 30 -gravity northwest -draw "text 690,487 '55 (0001 - 0055)'" -fill WHITE -pointsize 20 -gravity northwest -draw "text 582,534 'DATE'" -fill "rgb(124,124,124)" -pointsize 30 -gravity northwest -draw "text 690,534 '5/18/2011'" -fill WHITE -pointsize 20 -gravity northwest -draw "text 582,578 'NOTES'" -fill "rgb(124,124,124)" -pointsize 30 -gravity northwest -draw "text 690,578''"' -resize 2048x1168 -channel rgb -normalize -flatten Z:\Test\shots\CF_124_010\composites\CF_124_010_v02_cc\2048x1168\CF_124_010_comp_v02.0000.dpx

[stevepugh]

Hi all, a followup after further testing - I stripped out most of that abominable text drawing string (sorry for making anyone slog through it), and have discovered the following -

Just doing a compose over my 'source' frame and writing out a DPX file looks great:

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convert.exe -composite -gravity center CF_124_010_comp_v02.0010.dpx "S:\_Degobah4.0\Images\Slates\GenericSlate_R05.0001.tga" CF_124_010_comp_v02.0000.dpx

However, the minute I add even one text operator, I get a 32-bit DPX file with embedded alpha, which the format does not support and which causes pain and sorrow to rain down upon me:

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convert.exe -composite -gravity center CF_124_010_comp_v02.0010.dpx "S:\_Degobah4.0\Images\Slates\GenericSlate_R05.0001.tga" -fill WHITE -font "c:\WINDOWS\Fonts\HelveticaNeueLTCom-Md.ttf" -pointsize 20 -gravity northwest -draw "text 582,373 'PROJECT'" CF_124_010_comp_v02.0000.dpx

Does this jog any ideas among the collective memories of the group?

Best,
Steve

[fmw42]

try a more correct syntax (see http://www.imagemagick.org/Usage/basics/#cmdline). I don't know if that will help or not.

convert.exe CF_124_010_comp_v02.0010.dpx ( "S:\_Degobah4.0\Images\Slates\GenericSlate_R05.0001.tga" -fill WHITE -font "c:\WINDOWS\Fonts\HelveticaNeueLTCom-Md.ttf" -pointsize 20 -gravity northwest -draw "text 582,373 'PROJECT'" -alpha off ) -gravity center -composite -depth 10 CF_124_010_comp_v02.0000.dpx

[stevepugh]

Thank you, I'll give that a go - this particular project has been sliced/diced/folded/stapled/spindled/mutilated more times than I'd care to count since its start, so it shouldn't surprise me that things might have gotten garbled out of order at some point. Will post how it turns out.

Thanks,
Steve