A lot of work we do at the CCI uses scanning confocal microscopes, which have the advantage that the operator can pick the number of pixels in X and Y that will make up the final image.
For camera-based systems this is a less simple endeavour as the array of the CCD chip is fixed. For this reason, we may want to downsample or bin our images. In this post we’ll cover a bit of theory and details on how (and why) to bin your images.
In the last post, we looked at the following image to decide if an intensity of 2000 at the tip of the arrowhead was bright or dim. Without knowing the bit depth of the image it’s impossible to tell.
We posed that if this was a 12bit image, that’s fairly bright (2000/4096) but if it’s a 16bit image, then it’s very dim (2000/65536). But why would these two conditions look the same? The answer lies in the histograms and transfer functions…
In the list of things that everyone who uses a microscope should know, this has to be near the top and yet I find a surprising number of people are either never taught it or don’t fully grasp the idea of Bit Depth. In this post and Part 2, we will deal with (almost) everything you need to know about bit depth, dynamic range and image histograms.