Bilddifferenz

Bilddifferenz, also known as image differencing, is a technique used in computer vision to detect changes between two images of the same scene. It is a straightforward method that involves subtracting one image from another. The resulting image, often called a difference image, highlights areas where pixel intensity values have changed.

The process typically begins with acquiring two images. These images are then aligned to ensure that any differences observed are due to changes in the scene itself, not variations in camera position or orientation. Pixel-wise subtraction is performed, where the intensity value of each pixel in the first image is subtracted from the corresponding pixel in the second image. Areas that remain unchanged will have a difference value close to zero, appearing black or dark in the difference image. Areas where significant changes have occurred will have a non-zero difference value, appearing brighter.

Bilddifferenz has various applications. It is commonly used in surveillance systems to detect motion or intrusions. In quality control, it can identify defects or alterations in manufactured products. Medical imaging can utilize this technique to monitor the progression of diseases or the effectiveness of treatments by comparing scans taken at different times. Despite its simplicity, the effectiveness of Bilddifferenz can be influenced by factors such as lighting conditions, noise, and minor scene variations. More advanced techniques often build upon this fundamental concept to achieve more robust change detection.