2.1. File Formats

OK, so 8 bits are clearly not enough. You learned in Chapter 1 that HDR images are made of 32-bit floating-point numbers. This is the image data that sits in the computer memory when an HDR image is edited or displayed. We are talking about huge chunks of data here, much bigger and with a different structure than the regular 8-bit image. So we need new image formats that can store that HDR data.

Each image format has its own way of wrapping all this data into an actual file on disk. Important for us are some key elements: How good do they preserve the dynamic range? How widely are they understood? And most important, how much space do they take?