Resizing images (jpeg or decompressed image)

Question

In my last question I asked whether there was a better way to rotate images than I had thought of. I ended up discovering jpegtran and have since found libjpeg-turbo.

Now I am looking for a better way to resize the images (jpegs) than imagemagick and graphicsmagick.

Is there a specialized commandline tool to resize the images in a more efficient way than imagemagick or graphicsmagick? Maybe the resizing can be done on the GPU using opencl or opengl?

The provided hardware is the same as in the other post:

• Intel Atom D525 (1,8 Ghz)
• Mobility Radeon HD 5430 Series
• 4 GB of RAM
• SSD Vertility 3

Answer 1

Check this link out: http://leocharre.com/articles/faster-image-resizing-in-linux/

In particular the author mentions that imgresize is faster than imagemagick, and epeg is extremely fast.

epeg (http://www.systhread.net/texts/200507epeg1.php) seems quite well documented for generating thumbnails. If the quality is good enough, this could be the solution.

Answer 2

• OpenCL is a standard for cross-platform, parallel programming of modern processors found in personal computers, servers and handheld/embedded devices. It's directly supported by ATI. You'll need to get AMD APP SDK (formerly known as AMD Stream SDK) to get GPU support (also check out this getting started guide).

• Take a look at Intel's IPP - Integrated Performance Primitives. It's a multi-threaded software library of functions for multimedia and data processing applications. Among other features, it's has functions to resize images (bilinear, nearest neighbor, etc). Unfortunately, it is not free (cheapest version costs $199).

• VIPS is a free image processing system. It claims that compared to most image processing libraries, VIPS needs little memory and runs quickly, especially on machines with more than one CPU. See the Speed and Memory Use page for a simple benchmark against other similar systems.

Answer 3

You can actually do a lot of bulk processing like this with GIMP's CLI options.

http://www.gimp.org/tutorials/Basic_Batch/