Film-Tech Forum ARCHIVE: Parsing image MXF file

This is topic Parsing image MXF file in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Harold Hallikainen (Member # 5405) on 10-24-2018, 05:37 PM:

I'm interested in determining the X'Y'Z' code values for a pixel in the middle of the screen in a DCP in the middle of the reel. I'm guessing there is software that will convert the MXF to a series of still frames and then software that can tell me the X'Y'Z' code values of a pixel in the middle of the frame. But, I've never done it! Any help would be great! I'm trying to verify that some test content indeed has the correct code values for SMPTE peak white.

Thanks!

Harold

Posted by Carsten Kurz (Member # 5396) on 10-24-2018, 05:56 PM:

If I remember right, Carl has written a tool that does exactly that...

Let me see...here:

http://carlh.net/dumpxyz

I think it's been a while since he worked on it, and some links there seem to be broken. But I'm sure he will help you with it.

DCP-o-matic has an XYZ video waveform monitor, but so far I couldn't convince Carl to implement an interactive XYZ cursor readout.

- Carsten

Posted by Harold Hallikainen (Member # 5405) on 10-24-2018, 07:25 PM:

EXACTLY what I wanted! THANKS!

Posted by Scott Norwood (Member # 30) on 10-24-2018, 09:23 PM:

Oh, that is nice.

In the past, I have done this in a very convoluted way, using asdcp-test to un-MXF the MXF, converting the j2c file to PNG, and then using a tool from the Imagemagick tool set to give the RGB values:

convert <filename> -format "%[pixel:s.p{XXX,YYY}]\n" info:

(where XXX and YYY represent the pixel location)

I think that Imagemagick now handles XYZ colorspace natively, so there may be some steps that can be skipped.

The above-described way is far easier. Thanks!