Endoscope system, processor device, and method for operating endoscope system

A processor device that performs system control and image processing of an endoscope system having a light source and an endoscope that images an observation target irradiated with light emitted from the light source, the processor device comprising:

• an image acquiring unit that acquires an endoscope image obtained by imaging the observation target;
• a baseline information calculating unit that calculates baseline information by using the endoscope image or a display endoscope image generated by using the endoscope image, the baseline information being information about light scattering characteristics or light absorbing characteristics of the observation target and information that is at least not dependent on particular biological information;
• a region setting unit that sets, by using the baseline information, a calculation region in which an index value is to be calculated, the index value indicating a state of the observation target;
• and
• an index value calculating unit that calculates the index value in the calculation region set by the region setting unit, by using the endoscope image or the display endoscope image generated by using the endoscope image,
• wherein the baseline information calculating unit calculates the baseline information by using a plurality of the endoscope images with different kinds of illumination light used for imaging.

A method for operating an endoscope system including a light source, an endoscope, and a processor device, the endoscope imaging an observation target irradiated with light emitted from the light source, the processor device performing system control and image processing, the method comprising:

• a step of acquiring, by an image acquiring unit, an endoscope image obtained by imaging the observation target;
• a step of calculating, by a baseline information calculating unit, baseline information by using the endoscope image or a display endoscope image generated by using the endoscope image, the baseline information being information about light scattering characteristics or light absorbing characteristics of the observation target and information that is at least not dependent on particular biological information;
• a step of setting, by a region setting unit by using the baseline information, a calculation region in which an index value is to be calculated, the index value indicating a state of the observation target;
• and
• a step of calculating, by an index value calculating unit, the index value in the calculation region set by the region setting unit, by using the endoscope image or the display endoscope image generated by using the endoscope image,
• wherein in the step of calculating, the baseline information is calculated by using a plurality of the endoscope images with different kinds of illumination light used for imaging.