Method for monitoring distribution of structures on surface or of particles in space

The invention relates to a method for monitoring the distribution of structures on a surface or of particles in space. An optical image of the distribution is produced using video technology, for example. This image is then broken down into pixels, the average brightness of each pixel is determined, and the differences between the brightness values of adjacent pixels are calculated along pre-selected rows. These differential values are recorded on a data carrier and/or output in such a way that a correlation of the differential values with the position of the pixels is preserved on the image. This is used to determine at which points there are inhomogeneities in the distribution of the structures on the surface or the particles in space. The method can be used for example for assessing the homogeneity of surfaces, for detecting surface flaws and for monitoring the opening angle and the homogeneity of a directed spray.