  Among the group of extrasolar planets, transiting planets provide a great
opportunity to obtain direct measurements for the basic physical properties,
such as mass and radius of these objects. These planets are therefore highly
important in the understanding of the evolution and formation of planetary
systems: from the observations of photometric transits, the interior structure
of the planet and atmospheric properties can also be constrained. The most
efficient way to search for transiting extrasolar planets is based on
wide-field surveys by hunting for short and shallow periodic dips in light
curves covering quite long time intervals. These surveys monitor fields with
several degrees in diameter and tens or hundreds of thousands of objects
simultaneously. In the practice of astronomical observations, surveys of large
field-of-view are rather new and therefore require special methods for
photometric data reduction that have not been used before. In this PhD thesis,
I summarize my efforts related to the development of a complete software
solution for high precision photometric reduction of astronomical images. I
also demonstrate the role of this newly developed package and the related
algorithms in the case of particular discoveries of the HATNet project.
[abridged]
