LabVIEW
IMAQ convert gray scale image to RGB image
It is too bad that the LabVIEW Vision Functions are so minimally documented, with so few examples. Understanding Color is One of the Mysteries!
So you want to take a Grayscale Image, which has no color information, and "colorize" it. Let's assume you have a 16-bit Grayscale Image -- the pixel "values" can range from 0 to 65535. RGB Color uses a 32-bit pixel, devoting 24 bits to the "color space". This means that if you want a unique mapping from Gray to Color, there are 256 Color choices for every 16-bit pixel "Grayness". The various Color Palettes define a very tiny subset of these mappings.
But why bother? What is the advantage of "colorizing" a Grayscale image that has no color information? One answer is that with the right mapping, two pixels "near" each other in Grayscale representation (and hence largely indistiguishable by eye on a monitor, particularly one that doesn't have 16-bit "intensity depth") can appear very different if they are different colors (I was going to say "green doesn't look very different than red", but Red-Green color-blindness is quite common ...).
If you have an Image already, you can colorize it using a Property node:
The missing dotted line is the Error Line. The Image was generated with a background Pixel value consisting of a Gaussian with mean "Bias" and Standard Deviation "Noise", on which was super-imposed an Image (I thiink it was a series of lines) having amplitude "Intensity", so Intensity/Bias was "Signal-to-Noise". Coloring it made the (faint) Gray image much easier to see.
I was mentoring a BME undergraduate who has probably now finished her PhD, and haven't thought about these thorny problems for a few years ...
Bob Schor
