1)   UnJpeg 1.5
UnJPEG is a professional tool, specially designed to help you recover your images, damaged by JPEG compression. UnJPEG performs JPEG artifact and blotchy-look removal, median noise reduction, smooth image resizing, contrast and crispness control.

 2)   MacImage Resizer 1.0.1
Batch Image Resizer made for digital photographers and webmasters alike. Easy to use interface which is efficient. It allows you to either resize by changing JPEG image quality or by reducing the dimension of the images.