Patent ID: 8854445

Claim:
An endoscope apparatus comprising: an image pickup device equipped with a color separation filter that color-separates and receives returning light of light radiated onto a subject by an illumination device to pick up an image of the subject; an emphasis processing circuit that performs emphasis processing on sharpness of an image signal based on the image pickup device; a storage device that stores information for modifying the processing contents of the emphasis processing circuit according to a type of the image pickup device and spectral characteristics of the returning light incident on the image pickup device which differ depending on whether a first observation mode in which image pickup is performed under illumination of white light or a second observation mode in which image pickup is performed under narrow band illumination light; in the second observation mode, a first matrix circuit that performs matrix calculation for generating color signals of G and B from an image signal based on the image pickup device, and a signal intensity ration calculation circuit that dynamically calculates a signal intensity ration between the G and B color signals based on changes according to the returning light from the subject in field or frame units in a state where a coefficient of the matrix calculation performed by the first matrix circuit is set according to the type of the image pickup device; and a control circuit that performs control of modifying the processing contents of the emphasis processing circuit based on the information of the storage device, wherein the storage section stores, when the observation mode is the first observation mode, first information for setting an image signal to be subjected to emphasis processing by the emphasis processing circuit to a luminance signal and two color difference signals, and stores, when the observation mode is the second observation mode, second information for setting an image signal to be subjected to emphasis processing by the emphasis processing circuit to a luminance signal and one color difference signal, the first and second information being stored as the information for modifying processing contents of the emphasis processing circuit, in the first observation mode and the second observation mode, the emphasis processing circuit performs emphasis processing on the color difference signal in the image signal with a smaller emphasis characteristic than on the luminance signal in the image signal in a frequency domain on a high frequency side having a higher frequency, and only in the second observation mode, the control circuit performs control to generate the luminance signal which reflects the signal intensity ration dynamically calculated by the signal intensity ration calculation circuit as the luminance signal in the second observation mode.