
Unblur Image
Motion blur, missed focus, and noise are three different problems
When the camera moves during the exposure, every point in the scene is drawn into a short line, and the whole frame smears in the same direction. When the lens is focused too near or too far, each point is spread into a disc instead, evenly in all directions. When the light is low, the sensor's own noise and the camera's compression smooth the fine texture without a direction to it. The three need different handling, and the first is the one where a real reversal is possible, because a line preserves some of the order of what it smeared, while a disc throws that order away. Choosing the wrong approach is the most common way an unblur image attempt makes a frame worse.






