On Mar 9, 2010, at 10:53 AM, Maria Calvo wrote:
> Hello everybody,
>
> We have a "problem" when doing Stacks with images (32 bits) that have
> diferent ranges of their pixel values . ImageJ takes one range of one image
> to decide the color scale. But then, ImageJ aplies this color-scale to all
> the images of the Stack, so that if there is any image that is more intense
> than the first one, this last one is very saturated or otherwise it can be
> almost all dark, even if this image alone (this is when is not in a stack)
> looks very well.
> The image appearance can be restored by threshold reseting, but then
> the other images in the stack are rescaled again.
>
> Is it because image depth is infinite (32 bits)? Can this be avoided somehow?
>
> I hope you can help us. Thanks a lot.
You can avoid this problem by converting the n image stack to an n channel hyperstack. This example macro creates a 25 channel hyperstack containing images with pixel value ranges that vary from 0-1 to 0-15594.
n = 25;
newImage("Demo", "32-bit Ramp", 512, 512, n);
run("Macro...", "code=v=v*pow(z+1,3) stack"); // Process>Math>Macro
run("Stack to Hyperstack...",
"channels="+n+" slices=1 frames=1 display=Grayscale");
for (i=1; i<=n; i++) {
Stack.setChannel(i);
resetMinAndMax;
getStatistics(pixels, mean, min, max);
print(i+": "+min+"-"+max);
}
Locked
