how to know pixel color using t_sampler in jocl

问题

I want to detect peaks in a binary image using jocl. The definition of my peak is a combinition of colered pixels (shown in the image)

how to use t_sampler to know pixel color?

const sampler_t smp = CLK_NORMALIZED_COORDS_FALSE | //Natural coordinates
                      CLK_ADDRESS_CLAMP | //Clamp to zeros
                      CLK_FILTER_NEAREST; //Don't interpolate

PS: my image is a binary image

来源：https://stackoverflow.com/questions/38340383/how-to-know-pixel-color-using-t-sampler-in-jocl