XnConvert is an easy image converter for graphic files, photos and images available on Windows, MacOSX and Linux.
ImBatch is a batch image processor with a nice graphical user interface. It will allow you to edit multiple image files at the click of a button by using scripts. The script will be created by combining Tasks.
ImBatch vs BatchPhoto opinions
ImBatch is free for home use and in addition to 50+ available batch image processing tasks, supports custom scripts with pascal syntax
GraphicConverter is computer software that displays and edits Raster graphics files. It also converts files between different formats.
With BIMP you can apply a set of manipulations to an entire group of images! It provides an easy to use interface and a lot of batch functions:
Convert hundreds of images for your convenience and easy sharing. Supports TIFF, JPEG, RAW, PNG, BMP, EPS, PDF, PSD, TGA, and many other image formats.
Image Conversion Tool allows you easily converts jpg, png, bmp, gif, tiff, heic and other images to pdf, eps, ico, odd, ps, psd and other formats and other formats.
Image Converter Plus is a multifunctional conversion and resizing tool for Windows operating system.