colored image to greyscale image using CUDA parallel processing

Question

I am trying to solve a problem in which i am supposed to change a colour image to a greyscale image. For this purpose i am using CUDA parallel approach.

The kerne code i

Answer 1

You still should have a problem with run time - the conversion will not give a proper result.

The lines:

1. uchar4 rgba = rgbaImage[absolute_image_position_x + absolute_image_position_y];
2. greyImage[absolute_image_position_x + absolute_image_position_y] = channelSum;

should be changed to:

1. uchar4 rgba = rgbaImage[absolute_image_position_x + absolute_image_position_y*numCols];
2. greyImage[absolute_image_position_x + absolute_image_position_y*numCols] = channelSum;