opencl stupid toy kernel

gistfile1.txt

const sampler_t sampler =
  CLK_NORMALIZED_COORDS_FALSE | CLK_FILTER_NEAREST | CLK_ADDRESS_CLAMP_TO_EDGE;

float add_color(float color) {
  return color + 0.75;
}

__kernel void identity(read_only image2d_t inputImage,
                       write_only image2d_t outputImage) {

  int2 dimensions = get_image_dim(inputImage);
  int width = dimensions.x, height = dimensions.y;

  int x = get_global_id(0), y = get_global_id(1);

  float4 pixel = read_imagef(inputImage, sampler, (int2)(x, y));

  float red = pixel.x, green = pixel.y, blue = pixel.z, alpha = pixel.w;

  float4 transformedPixel = (float4)(add_color(red), green, blue, alpha);

  write_imagef(outputImage, (int2)(x, y), transformedPixel);
}