Look up table

[Madhubalan]

Hi,

   How to create Lookup table for each R,G and B planes in IMAQ ColorUserLookup VI?

Regards

Madhubalan

 

[Klemen]

Hello,

depends on what you want to do. A cLUT (color lookup table) can be used to quickly alter the value of the pixel values based on your preference (the values are indexing the cLUT array).

Please see the attached code, where the 255 value on the red plane is replaced with 0 first using a cLUT and secondly with pixel by pixel access. The general basic idea of the lookup tables is reducing the calculation time.

Best regards,

K

[Madhubalan]

Hi Klemen,

               Suppose if i want to quantize the color in an image,i.e  reduces the number of distinct colors used in an image.

If have attached the example of an image defore and after quantization.

Thank you

[Topper_Harley]

Hi Madhubalan,

as fas as I know, there is no specialized function in NI Vision Module, that does exactly as you specified. You have to do it manually. It can be done on a by-pixel basis: get the color of each pixel, split into red, green, blue and replace their values as desired. In LabVIEW it is possible to define ranges in numeric case structures such as "0..32", "33..64" and so on. In the example below, all values between 0 and 32 will be replaced with the value 16.

Regards, Topper

[Madhubalan]

Hi Harley,

             can just convert it into 2011 and post it here.

Thank you

[Madhubalan]

Hi,

   In the attached Vi file ,i could able to get the color of each pixel,in this how can i reduce the distinct color of the pixel and how can represent it in the ouput image.

Thank you

[Klemen · Accepted solution]

Please see this thread, maybe it will help you:

http://forums.ni.com/t5/Machine-Vision/color-image-quantization/td-p/2545923

And here is your image reduced to 64 colors:

Best regards,

K

[Madhubalan]

Hi Klemen,

               It is working fine.

Thank you

[Madhubalan]

Hi Klemen,

               In above picture you have mentioned, it has reduced to 64 color,how can i find it in the code whether it is reduced to 64 color or not?

Thank you

[Klemen]

Hello,

Just count the number of instances of each element in the RGB vector (after the quantization). You can use the following vi: https://decibel.ni.com/content/docs/DOC-9801. Using the linked code, just check the size of the "count" output in the end.

Best regards,

K