We give diffraction gratings an analysis in the lensless camera’s construction, the reasons for their use in image processing, their use and the problems main positive factors associated with their consideration in the lensless camera’s construction. The diffraction gratings most common types examples that are currently used in the lens-free camera’s construction are given, their classification and approximate structure with giving their transfer functions mathematical description is given, and their use practical examples in solving various problems associated with image processing are considered. The various diffraction gratings basic advantages and lacks consideration analysis at lensless cameras construction and their use reasons are performed. Also, the questions connected with their further development at image processing construction and use in problems are considered.

The inverse problems current state a general characteristic in optics is given, the approaches to their solution, their incorrect and unstable solutions cause are considered, and recommendations for these drawbacks elimination are given. General approaches to solving inverse problems in images reconstruction obtained in lensless cameras based on different masks are also considered, and their advantages and disadvantages in comparison with lensless lenses are pointed out, as well as their further research directions are indicated.