I'm working on some finite element analysis code, and one of our commonly used troubleshooting tools is a graphical output of the large matrices that define the physical problem. However, as the problem sizes become large, the tools I've used in the past (libpng, libharu pdf) begin to take extremely long times to write the images to file.
My question: can anyone recommend a high-performance C++ image library, capable of outputting large images in some standard format (e.g. png, tiff, etc) efficiently? Furthermore, the matrices to be plotted are VERY sparse, meaning that most of the image canvas is actually empty; so although an image's resolution may be almost a gigapixel, there would be only about 20-30 pixels per row maximum.
I'd try http://www.openexr.com/ OpenEXR comes with an SDK for reading and writing. I/O never requires having the entire bitmap in memory.