Endoscope system and method of operating the same

1. An endoscope system comprising:

a plurality of semiconductor light sources that emit light having wavelength ranges different from each other;

a light source controller that performs control to cause the plurality of semiconductor light sources to emit a plurality of kinds of illumination light, which include first illumination light having a first light emission ratio and second illumination light having a second light emission ratio different from the first light emission ratio, while switching the plurality of kinds of illumination light according to a specific light emission order and a specific light emission period; and

a processor configured to:

pick up images of an object to be observed illuminated with each illumination light to acquire a plurality of images, the plurality of images including first images obtained using the first illumination light and second images obtained using the second illumination light;

give a static-image-acquisition instruction to acquire static images for storage of the respective images;

calculate shake amounts of the plurality of images acquired in a specific static-image-acquisition instruction period including a timing when the static-image-acquisition instruction is given, in which shake amount-calculation processing for calculating the shake amount varies for each of the images;

perform control to store the plurality of images in a static image-storage as the static images for storage in a case where a specific condition is satisfied with regard to the shake amount;

associate a display condition including a specific display order and a specific display time with the static images for storage, and store the display condition, the specific display order being an order from the first image to the second image, the specific display time being two or more frames for each of the first and second images; and

read out the static images for storage and the display condition, and display the static images for storage on a display while switching the static images for storage according to the display condition.

2. The endoscope system according to claim 1 , wherein

spectral images having a plurality of colors are included in each of the images, and

the shake amount-calculation processing includes first shake amount-calculation processing for calculating a first shake amount from a spectral image, which has a first color, of the first images, and second shake amount-calculation processing for calculating a second shake amount from a spectral image, which has a second color different from the first color, of the second images.

3. The endoscope system according to claim 2 , wherein

the first illumination light includes more light, which has a short wavelength, than the second illumination light, and

the first color is a blue color and the second color is a green color.

4. The endoscope system according to claim 1 , wherein

the processor is configured to store each of a first image having a smallest shake amount with regard to the first images and a second image having a smallest shake amount with regard to the second images, among the plurality of images obtained in the specific static-image-acquisition instruction period, as the static images for storage.

5. The endoscope system according to claim 1 , wherein

the shake amount-calculation processing differs depending on an observation mode in which an image, which is an object of which the shake amount is to be calculated, is acquired.

6. The endoscope system according to claim 3 , wherein

the first shake amount-calculation processing is a first algorithm for calculating the shake amount using a blue spectral image, and the second shake amount-calculation processing is a second algorithm for calculating the shake amount using a green spectral image.