Posted by
Dianne Patterson on
Jul 28, 2009; 6:59pm
URL: http://imagej.273.s1.nabble.com/Blood-vessel-analysis-using-16-bit-image-tp3691611p3691618.html
It matters how you convert to 8 bit....you can lose all values above 256, if
you don't take pains to preserve them.
I do the following
# copy the 16 bit image to a new8
# Find the maximum intensity value in the image and put it in a variable
# Divide max by 255
# Use divisor to change the range of values in new8, then save it as 8-bit
char
When you are done, look at the old image and the new one...they should look
the same to you...and white values should be near 255.
-Dianne
On Tue, Jul 28, 2009 at 11:05 AM, Schaffer, Beverly <
[hidden email]>wrote:
> Hi Everyone,
>
>
>
> Thanks to everyone who responded to my previous email about imaging
> blood vessels. I've tried the skeletonize and analyze skeleton plug-ins,
> but they only work with an 8-bit grayscale image. The camera I am using
> takes a 16-bit picture. I have tried converting the image to 8-bit in
> ImageJ (type-8-bit) and then processing the image using skeletonize. All
> I get is a single straight line in the middle of the image.
>
>
>
> I've tried saving the image in AxioVision as a tif and then taking it
> into ImageJ, converting it to 8-bit (as above) with the same result when
> I process using skeletonize. I've also tried taking the tif image into
> photoshop and saving it as an 8-bit grayscale image and get the same
> result when I process with skeletonize.
>
>
>
> Any other ideas?
>
>
>
> Thanks!
>
>
>
> Beverly Schaffer
>
>
[hidden email]
>
>
--
Dianne Patterson, Ph.D.
[hidden email]
University of Arizona
SLHS 328
621-5105