I''ve been trying to work out how to read a column of image pixels in PD and then convert the greyscale values to the frequency parts of a spectogram. I've got as far as loading an image, and using pix_data to read the pixel values, but I have no idea and cant find a way to convert these into some form of spectogram that PD can read and play back as audio.

I'm also using a line to read each pixel value individually, which is slow. Is there a better way?