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Convert to J2C from DPX

Posted: 2017-02-22T16:54:19-07:00
by churchwa
I am trying to batch convert DPX>J2C and am having a few issues.

The main one being that IM keeps making the J2C file using the JP2 codec. i.e. it produces a file called test.j2c but when you try and open it the software says this is a JP2 file and not a J2C.

How can a force IM to convert to a J2C file?

Re: Convert to J2C from DPX

Posted: 2017-02-22T19:33:26-07:00
by fmw42
Assuming you are using a more current version of IM and openjpeg 2.1 or higher in your IM compile, then try prefacing your output with J2C:output.j2c

Also see http://www.imagemagick.org/script/jp2.php

Re: Convert to J2C from DPX

Posted: 2017-02-23T09:25:10-07:00
by churchwa
Thanks for the advice although I still get the same result using J2C:file.j2c

As a noob, can I ask. Having installed the latest version of IM can I assume the latest openjpeg is installed as well? (Using windows)

CMD gives me the following message after converting the file (regardless if I use the prefix or not):
convert: Deprecated fields cp_cinema or cp_rsiz are used
Please consider using only the rsiz field
See openjpeg.h documentation for more details
`OpenJP2' @ warning/jp2.c/JP2WarningHandler/236.

Re: Convert to J2C from DPX

Posted: 2017-02-23T10:20:54-07:00
by fmw42
Sorry I do not know about that.

What do you get from

Code: Select all

convert -version
Does it include JP2?

What version of openjpeg do you have on your system? You can find that from

Code: Select all

convert -list format
Perhaps it is a limitation of Imagick. Does it work fine using the command line in a terminal or PHP exec() command?

Re: Convert to J2C from DPX

Posted: 2017-02-23T10:56:40-07:00
by fmw42

Re: Convert to J2C from DPX

Posted: 2017-02-23T10:58:38-07:00
by fmw42
Is there really a difference? Do you know of openjpeg supports j2c?

Re: Convert to J2C from DPX

Posted: 2017-02-23T13:23:59-07:00
by churchwa
So convert -version gives:
Version: ImageMagick 7.0.5-0 Q16 x64 2017-02-20 http://www.imagemagick.org

And J2C is in the list of formats with the module being JP2. Seems I have version 2.1.2 of openjpeg.

I have tried both convert and magick as convert is now deprecated, and get the same output.

Re: Convert to J2C from DPX

Posted: 2017-02-23T13:26:22-07:00
by churchwa
fmw42 wrote:
2017-02-23T10:20:54-07:00

Perhaps it is a limitation of Imagick. Does it work fine using the command line in a terminal or PHP exec() command?
I am running it all from command line.

We are feeding in approx 50meg 4K files and the subsequent j2c files are only 1.2meg.
Does this sound right, seems very small.

I have done -quality 0 for lossless and the resolution comes out at 4k which is also correct.

Re: Convert to J2C from DPX

Posted: 2017-02-23T15:19:58-07:00
by fmw42
Sorry, I do not know the difference between JP2 and J2C. I could not find on Google any document that explained the difference other than suffix.