Legacy ImageMagick Discussions Archive

Hello,

I would like to AUTO-ROTATE a lot of image with imagemagick. My camera have the orientation sensors and the EXIF header are marked accordingly. My questions:

1) Can we use ImageMagick to autorotate images base on their EXIF tag orientation field?

2) I have a dual quad core XEON, can I benefit of all this power? Can Imagemagick send a picture to b process to all available cores?


Thanks for your time.

Claude

Modern versions of ImageMagick support auto-rotation.

Set the --enable-openmp configure command-line option to allow ImageMagick to take advantage of multi-processor systems for certain algorithms (e.g. blur, sharpen, unsharp mask, etc.).

Does it take advantage of the MP with the rotate argument?

Nope. We'll be adding additional MP algorithms over time but for proof-of-concept we limited the algorithms to anything convolution (e.g. blur).

cferron wrote:Does it take advantage of the MP with the rotate argument?

Distribute your images into four different folders, or use a clever naming scheme and then run IM four times in parallel, each with one fourth of the images to process.

However, the processing may get I/O bound.

I am also not sure that ImageMagick performs a lossless jpeg rotation- AFAIK, it doesn't. A lossless rotation is quite fast and will benefit very little from multi-core execution (MP execution may be even slower because of disk thrashing and/or thread synchonization). You might consider to use a different tool for the job (one which does lossless jpeg transforms).

Best regards, Klaus