OrbConvert converts your image files online. Amongst many others, we support PNG, JPG, JPEG, WEBP, GIF, SVG and TIFF. You can use the options to control image resolution, quality and file size.
From
Portable GrayMap
The Netpbm grey-scale format — one channel, uncompressed. Colour information is discarded, not converted.
All PGM conversionsTo
X BitMap
A plain-text image format that stores a bitmap as a C source array, historically for X11 cursors and icons. One bit per pixel, so it is black and white only.
All XBM conversions