Picture post processing Vision and Motion

[bezoky]

Hello all!

Im working on post-processing .TIF images using Vision and Motion modules.
Picture is loaded as array (grayscale U16) via IMAQ and displayed properly.
Then every pixel is scalled (multiply and offset).
Sadly the manipulated picture does not look changed properly.

For example: pixel value 40000(U16) [light grey] looks like 3000 [black]

Picture and VI (2016) is included.

Thanks for your responses.

[raphschru]

It looks like a color palette problem.

You are displaying a U16 Grayscale image on an image control that uses a U8 Grayscale palette.

By default, to convert from a U16 value to a U8 value, the IMAQ Image control uses a kind of dynamic mapping.

For example the lowest value is mapped to black, while the highest is mapped to white, no matter the absolute U16 values.

To have a better idea of the absolute U16 values, you can right-click your manipulated image -> 16-Bit Display Mapping -> Choose "Most Significant Bits". This way you will lose the 8 least significant bits of precision, but you will have a true idea of the real U16 values. Indeed, 0 (U16) is mapped to black, while 65535 (U16) is mapped to white.