Using a 3D LUT

[venkatsiddareddy]

Hi,
I have a look up table in .3dl format. Currently I am using after effects or some other tool to apply the look up table. However the process is very slow. I am planning to use IM to convert my images using the same look up table.

I have tried using the Hald Clut but I am very new to IM and could not succeed.
Can some one please help me in converting the look up table in to a hald clut and apply the same on multiple images?

Please help

Thanks
Venkat

[fmw42]

Sorry I know nothing about .3dl format luts. I also do not know whether IM can even handle that. See the list of formats.

convert -list format

where it is not listed.

However to use hald-cluts, you first create a hald image of the color resolution desired, for example

convert hald:3 hald3_lut.png

Then take the resulting hald image and process it with the same processing that you presumably used to create the .3dl lut. That is for example, apply the same processing steps either in IM or Photoshop or whatever tool to the hald3_lut.png to create hald3_lut_processed.png

Now to use that hald3_lut_processed.png, you simply use:

convert image hald3_lut_processed.png -hald-clut resultimage


see http://www.imagemagick.org/Usage/color_mods/#hald-clut

[venkatsiddareddy]

Hi,
thanks for your reply.
I successfully used hald clut to convert my image using your suggestion.
However if use

Code: Select all

convert test.dpx hald.png -hald-clut converted.dpx

the image is completely wrong. but if use

Code: Select all

convert test.dpx hald.png -hald-clut -depth 16 converted.tiff

I get the desired output. I tried depth -10 for dpx but even then the resultant image is not proper.
Can some one help me in converting my DPX files in to DPX again using hald-clut?

Thanks in advance
Venkat

[anthony]

Sounds like a bug in the DPX coder handling. Hald assumes the image is in RGB colorspace, and I believe DPX uses a 'log' (rgb in a logarithmic scale) color format. (its a guess on my part I don't use DPX)

What happens with a unprocessed HALD image? Prehaps you should report it in the BUG's forum with a complete set of (minimal) commands, and input and output example images.