Re : IMAQ absolute difference issue

[TiTou]

Hi all,

Have a look a the attached VI (LV 8.20).

Here is what it does :
    1. creates 3 8-bit grayscale images (A, B, sous)
    2. sets images sites (same size for the 3)
    3. fill each image with a different gray level (the 3 levels are setable)
    4. perform an IMAQ absolute difference "abs(A - B) = sous"

With the default values I set ( 200 for image A, 50 for image B, and 0 for image sous) at the end the result is, as I expect :
    A is still at 200
    B is still at 50
    sous is at 150

Now if I set :                                                 I expect :                           instead I get :
    A any level between 0 and 255                  A still at anything                  A at anything
    B level = 0                                                  B still at 0                             B at anything
    sous level = 0                                             sous at anything                  sous at anything

Is there a good reason for this  ?

[Olivier M]

Hi,

The problem in your VI is the name of your images.
Indeed, when you take A=255 B=0 and sous=0, the images B and sous have the same name and consequently you have the following result :B=sous=0
Take care to give different names to your images as attached in this post.

Sincerly,

Olivier

[TiTou]

wooops... indeed

thanks for your help... sometimes I get so focus on the process that I completely miss everything...