THE EFFECT OF THE MULTIFUNCTION METHOD OF REGISTERING IMAGES OF OBJECTS WITH A LARGE RANGE OF BRIGHTNESS ON THE MODULATION TRANSFER FUNCTION OF THE RESULTING IMAGE

Abstract

When photographing of objects with large range of brightness, some information may be lost. The main reasons for the loss of information when photographing these objects are insufficient dynamic range of the input signal to the dynamic range of the image detector. To reduce loss of the information when photographing in a large range of brightness within a frame used multiplicative, additive and multifunction methods of image registration are used. If multifunction method of image registration is used exposing the photosensitive sensor through pre-built frequency selective filter-mask of optical image of the photographing object and images of uniform brightness screen is carried out. An expression for the modulation transfer function of the resulting image formed using the multifunction method of registering images of photographing objects with a large range of brightness is obtained. The influence of the parameters of the image registration process using the multifunction method on the modulation transfer function of the multifunction mage is analyzed. With the masking coefficient , there is no compression of the dynamic range of the input signal. When the contrast of low-frequency components of the signal spectrum is reduced, the case corresponds to a full equalization of their intensity. At negative values , a reverse of contrasts is observed at low spatial frequencies. At high spatial frequencies, the shape of the modulation transfer function determines the brightness of the source of additional exposure. The expression for the modulation transfer function of the resulting image can be used when conducting theoretical studies of the effect of the process of the multifunction method of registering images on the shooting efficiency.