How can I transfer vision data into another sub vi?

[dx7]

I want to transfer my vision data results from one sub vi to the input of another sub vi.
First I tried to connect an Image Display from the front panel with an exit of the Sub Vi but then the error message "Not an image" occurs.
How can I solve the problem?

[DOC (-) doc]

Well there are two kinds of data with vision :

the fisrt one is "external" results, as for any other operation, you input an image and output the results and the image.
the second one is "internal", like patern matching setups, scaling, ROI etc, the data is included in the image and you need special VIs, when they exist to extract the data.

What is the exact data you want to extract from your image

[dx7]

It´s a result of an operation. I want to extract a region of interest of an image and put this result into another Sub-VI.

[DOC (-) doc]

then you need to use the "IMAQ extract" function in "image manipulation"