Method of controlling endoscope and endoscope

A method of controlling an endoscope comprising a first light source section that emits white illumination light, a second light source section that emits narrow-band light having a wavelength band narrower than that of the white illumination light, and an imaging section that captures a region to be observed by an imaging device comprising detection pixels of plural colors, the method comprising:

• causing the imaging section to output a captured image signal including a return light component of the white illumination light from the region to be observed and a return light component of the narrow-band light from the region to be observed, wherein the captured image signal comprises a red image signal, a green image signal, and a blue image signal;
• generating captured images of red, green, and blue colors based on the red, green, and blue image signals, respectively, wherein the captured images include a first captured image, and of the captured images, the first captured image contains a most return light component of the narrow-band light emitted from the second light source;
• changing a brightness level of the first captured image relatively to brightness levels of captured images based on the red and green signals;
• dividing the first captured image and a second captured image which has a different reference color from that of the first captured image into common plural image areas;
• obtaining a ratio of a brightness value of each image pixel of the first captured image and a brightness value of a pixel, having a same image positional relationship with each pixel of the first captured image, of the second captured image;
• extracting pixels, of the first and second captured images, whose ratio is equal to or larger than a threshold value, as characteristic pixels;
• obtaining a number of characteristic pixels in each image area of the first and second captured images;
• extracting image areas, of the first and second captured images, whose number of characteristic pixels is equal to or larger than a threshold value, as characteristic image areas;
• and
• selectively changing a brightness level of the characteristic image area of the first captured image.

An endoscope, comprising:

• a first light source section that emits white illumination light;
• a second light source section that emits narrow-band light having a wavelength band narrower than that of the white illumination light;
• an imaging section that captures a region to be observed by an imaging device having detection pixels of plural colors;
• and
• a control section,
• wherein the control section causes the imaging section to output a captured image signal including a return light component of the white illumination light from the region to be observed and a return light component of the narrow-band light from the region to be observed, wherein the captured image signal comprises a red image signal, a green image signal, and a blue image signal,
• wherein the control section generates captured images of red, green, and blue colors based on the red, green, and blue image signals, respectively,
• wherein the captured images include a first captured image, of the captured images, the first captured image contains a most return light component of the narrow-band light emitted from the second light source, and
• wherein the control section changes a brightness level of the first captured image relatively to brightness levels of captured images based on the red and green signals;
• a divider for dividing the first captured image and a second captured image which has a different reference color from that of the first captured image into common plural image areas;
• an integrator for integrating brightness values in each image area of the first captured image to obtain an integrated brightness value of each image area of the first captured image, and for integrating brightness values in each image area of the second captured image to obtain an integrated brightness value of each image area of the second captured image;
• a unit for obtaining a ratio of the integrated brightness value of each image area of the first captured image and the integrated brightness value of the image area, having a same image positional relationship with each image area of the first captured image, of the second captured image;
• an extractor for extracting image areas, of the first and second captured images, whose ratio is equal to or larger than a threshold value, as characteristic image areas;
• and
• a selector for selectively changing a brightness level of the characteristic image area of the first captured image.

An endoscope, comprising:

• a first light source section that emits white illumination light;
• a second light source section that emits narrow-band light having a wavelength band narrower than that of the white illumination light;
• an imaging section that captures a region to be observed by an imaging device having detection pixels of plural colors;
• and
• a control section,
• wherein the control section causes the imaging section to output a captured image signal including a return light component of the white illumination light from the region to be observed and a return light component of the narrow-band light from the region to be observed, wherein the captured image signal comprises a red image signal, a green image signal, and a blue image signal,
• wherein the control section generates captured images of red, green, and blue colors based on the red, green, and blue image signals, respectively,
• wherein the captured images include a first captured image, of the captured images, the first captured image contains a most return light component of the narrow-band light emitted from the second light source, and
• wherein the control section changes a brightness level of the first captured image relatively to brightness levels of captured images based on the red and green signals;
• a divider for dividing the first captured image and a second captured image which has a different reference color from that of the first captured image into common plural image areas;
• a unit for obtaining a ratio of a brightness value of each image pixel of the first captured image and a brightness value of a pixel, having a same image positional relationship with each pixel of the first captured image, of the second captured image;
• an extractor for extracting pixels, of the first and second captured images, whose ratio is equal to or larger than a threshold value, as characteristic pixels;
• a unit for obtaining a number of characteristic pixels in each image area of the first and second captured images;
• a unit for extracting image areas, of the first and second captured images, whose number of characteristic pixels is equal to or larger than a threshold value, as characteristic image areas;
• and
• a selector for selectively changing a brightness level of the characteristic image area of the first captured image.

An endoscope, comprising:

• a first light source section that emits white illumination light;
• a second light source section that emits narrow-band light having a wavelength band narrower than that of the white illumination light;
• an imaging section that captures a region to be observed by an imaging device having detection pixels of plural colors;
• and
• a control section,
• wherein the control section causes the imaging section to output a captured image signal including a return light component of the white illumination light from the region to be observed and a return light component of the narrow-band light from the region to be observed, wherein the captured image signal comprises a red image signal, a green image signal, and a blue image signal,
• wherein the control section generates captured images of red, green, and blue colors based on the red, green, and blue image signals, respectively,
• wherein the captured images include a first captured image, of the captured images, the first captured image contains a most return light component of the narrow-band light emitted from the second light source, and
• wherein the control section changes a brightness level of the first captured image relatively to brightness levels of captured images based on the red and green signals;
• a divider for dividing the first captured image and a second captured image which has a different reference color from that of the first captured image into common plural image areas;
• and
• an integrator for integrating brightness values in each image area of the first captured image to obtain an integrated brightness value of each image area of the first captured image, and for integrating brightness values in each image area of the second captured image to obtain an integrated brightness value of each image area of the second captured image.