Statistics Colour Rendering | ![]() |
This tool allows you to combine a background image (raw FMRI or high resolution MRI) image with one or two statistics images. The statistics image(s) must be in registration with the background image.
The different programs are:
Select all of the images, and then enter a threshold (Min) for the stats image(s). Any stats values below this will not appear in the colour rendered output. Any stats above Max will appear, all with the same colour as the Max value gets (ie yellow or light blue). You don't need to change the "Min" and "Max" settings unless you want to vary the display range - for example if the background image looks very dark when scaled to its min and max.
The colourmap type option lets you choose Solid colours (you don't see any sign of the background images within the colour blobs) or Transparent colours (you will see through the colour blobs to the background intensity).
In general the intensity values within colour rendered images bear no simple relationship to the original stats values. However, in the case of rendering Solid colours with Floating point output type, the red-yellow blobs will contain the actual values of the stats input image (but the blue blobs will not).
If you want to do 3D rendering in MEDx with the results of stats colour rendering, you should use solid colours and choose Integer output type. Then in the 3D rendering GUI either select Material Iso-Surface for solid 3D rendering or Transparent Summation for transparent rendering - the latter option means that activations just under the cortical surface will be visible. The images may appear quite dark - in this case you can always brighten them (after "printing" them to tiff files) using the program "display".