Imagenator is a straightforward tool for converting batches of images between various formats: BMP, EXR, GIF, HDR, ICO, J2K, JP2, JPG, PBM/ PGM/ PPM (both RAW and ASCII), PFN, PNG, TGA, TIF, WAP, XPM.

The program supports a range of format-specific options. Export to ICO, say, and you can select an icon resolution from 16x16 to 256x256; JPEGs have Quality and Subsampling options; EXRs give you control over image compression (you can choose lossy, lossless, or none at all), and more.

You're also able to set the maximum size (width or height) of an image. Anything larger will be resized with your choice of algorithm (box, bicubic, bilinear, bspline, Catmull-Rom, Lanczos3).

An Output Pattern option helps to define custom output folders and file names. Something like {M}-{d}\{fn}-{n} , for example, will generate a subfolder based on the current month and day, before using the original file name, and adding a number from this batch (Feb-4\Filename2.jpg, for example).

When you've finished, clicking Start quickly processes your source files, saving the results according to your specified rules.