With Batch Image Converter a user can convert images between 25 different formats directly from Windows. The program supports these formats: BMP, JPG, GIF, PNG, TIF, SGI, PSD, WMF/EMF, PCX, DDS, TGA, RAW, CUT, DCX, LBM, LIF, MDL, PCD, PIC, PNM, PSP, WAL, ACT, PAL, and HDR. It is possible to control various options for different formats: JPG compression level, GIF dithering and palette, PNG bit depth, and preview results inside the program. User can also adjust brightness, contrast, and saturation; easily set new names for the processed images by using original files" names, numbers, and other arbitrary characters. Program can process images even faster if user"s computer has multi-core CPU, or has several CPUs installed.
Source: http://www.binarymark.com/Products/BatchImageConverter/default.aspx