ImageMagick is a software suite to create, edit, and compose bitmap images. It can read, convert and write images in a variety of formats (about 100) including GIF, JPEG, JPEG-2000, PNG, PDF, PhotoCD, TIFF, and DPX.

XnConvert is an easy image converter for graphic files, photos and images available on Windows, MacOSX and Linux.

Saving images for web/email/other media with the best compression ratio and quality is a difficult task if you don’t have the right tools. Choosing the right format then choosing the right parameters are the key factors of smaller files.

Converseen is a free cross-platform batch image processor for Windows and Linux that allows you to convert, resize, rotate and flip an infinite number of images with a mouse click.

Convert and Rename images in batch mode

Support JPEG, BMP, GIF, PNG, TIFF and JPEG2000

Resize, crop, change color depth, apply color effects, add text, watermark and border effects

Rename images with sequential number

Search and replace texts in the file names

Preview conve.

-Combines PNGOUT, OptiPNG, and DeflOpt to create the smallest PNGs -No image quality is lost — only file size -Converts JPG, GIF, TIFF, and BMP files to PNG -Ultra-configurable

PNGGauntlet is a .NET program that uses Ken Silvermans PNGOUT, OptiPNG and DeflOpt to optimize PNG fil.

Create email-friendly images, resize in batches, convert formats, and compress using high-quality filters. Integrated in Windows Explorer, it offers high-res settings, watermarking, a profiles library, PDF creation, and supports devices like iPad and iPhone.

XnShell is a free File Explorer extension that installs a number of image-related tools in the right-click context menu, including a thumbnail preview, image conversion to a wide variety of formats, image resizing, editing image IPTC...

Image Resizer for Windows is a utility that lets you resize one or more selected image files directly from Windows Explorer by right-clicking.

Switcheroo is designed to give you a simple, quick, and easy-to-use tool to convert and manipulate your images in whatever way you like. It is built on top of the most advanced image editing libraries, ImageMagick.

GraphicsMagick is the swiss army knife of image processing. Comprised of 282K physical lines (according to David A. Wheelers SLOCCount) of source code in the base package (or 952K including 3rd party libraries) it provides a robust and efficient collection of tools and libraries...

Oxipng is a multithreaded lossless PNG compression optimizer in Rust. It can be used via a command-line interface or as a library in other Rust programs.