Alignment of adjacent picture frames captured by a CLSM

The inverse relation between the magnification of a microscope and the size of the field of observation (picture frame) yields the requirement to compose a large, detailed picture of a studied object from a mosaic of picture frames. The main problem of the composition is with the correct alignment of adjacent picture frames, which is called registration. This alignment is accomplished according to the similarity of the border areas of the adjacent picture frames. The area of the adjacent picture frames which is common to both of them (overlapping) is an important parameter. The larger this area, the more simple is the alignment but the less efficient is the mosaic composition. Alignment like registration in general may require changes (normalization) of the intensity histogram and scale, compensation of deformations, and a combination of rotations and translations of the pictures. However, in the case of picture frames captured by an optical microscope with a reproducible controlled stage, like in our case of a CLSM (confocal laser scanning microscope) application, the required modifications of both picture frames can be reduced to translations only.