ImageMagick - a command-line image manipulation program, available for Windows, Mac and Linux. Unless you are server administrator, you probably never thought of resizing images using command line. However, after switching to command line, I never looked back at Photoshop for batch resizing.
Using command line is:
- Easy to expand - adding new sizes takes only one line of code;
- Easy to maintain - changing folders is as easy as changing one variable;
- Portable - I can save images on server, not only on my main computer.
If you neved worked with command line before, it all might look scary at first. However, with a bit of patience, you will find that it's actually very powerful tool.
Below is the bash script I wrote, simplified for more universal usage. It takes the following parameters (from you or from default values):
- set of output sizes;
- source file
- destination path (path must include % symbol, which will be replaced by output size, f.e. "800x600")
- optional signature image.
Then it resizes source image into every output size, applying a signature. For better understanding, please look throught the comments in source code.
The script requires:
- imagemagick - to install, follow instructions for your OS.
- python - I'm sure your PC already has it installed!
Tested in Ubuntu and Mac OS X.
How to use:
- save resize.sh to any folder on your computer.
- (optionally) edit the file and set default values for variables.
- open Terminal, navigate to this folder, and execute the following command:
bash resize.sh - follow instructions, sit back and enjoy!