Classification images: step edge.

<p>The black line shows the target profile. The blue curve is the “raw” classification image and the red curve the spatially normalized classification image. Classification image profiles peak inside the stimulus, at the location of the border. In most cases, there is also a negative peak at the background next to the border. The relative extent of the classification image profile compared to the target size is dependent on the size: with small 0.33 degree stimulus it encompasses the entire stimulus, but with large 1.33 degree stimulus, it covers just the border.