Any body knows how to implement Leave Color Effect in Premiere

The effect will leave a selected color unchanged, and convert other color into black and white.
The result from Premiere is very good. I wander anybody know how to implement.

Thank you.

Do you mean gray shades by "black and white"?
If you want to do this on an image using LEADTOOLS, you can use the following approach:
1. Define a region that contains the color or colors you want to keep.
2. Store the location of the region (region bounds).
3. Copy the region contents to a temporary bitmap.
4. Convert the original image to grayscale
5. Copy the temporary bitmap contents from step 3 back to the original image using the location information you stored in step 2.

The details depend on which LEADTOOLS version (14, 15, 16, etc.) and programming interface (Main OCX, .NET classes, DLL API, C++ Classes, etc.) you are using.

Have you already tried to implement this? If yes, what is the function you are trying to use?
If you can't get it to work, please send me 2 sample image: The source image before the effect, and the resulting image that has the desired effect.