Evaluation value calculation device and electronic endoscope system

Abstract

An electronic endoscope system includes a plotting unit which plots pixel correspondence points, which correspond to pixels that constitute an intracavitary color image that has a plurality of color components, on a target plane according to color components of the pixel correspondence points, the target plane intersecting the origin of a predetermined color space; an axis setting unit which sets a reference axis in the target plane based on pixel correspondence points plotted on the target plane; and an evaluation value calculating unit which calculates a prescribed evaluation value with respect to the captured image based on a positional relationship between the reference axis and the pixel correspondence points.

1 - 19 . (canceled) 
     
     
         20 . An electronic endoscope system comprising:
 a plotting unit configured to plot pixel correspondence points, which correspond to pixels that constitute an intracavitary color image that has a plurality of color components, on a target plane according to color components of the pixel correspondence points, the target plane intersecting an origin of a predetermined color space;   an axis setting unit configured to set a reference axis in the target plane based on pixel correspondence points plotted on the target plane; and   an evaluation value calculating unit configured to calculate a prescribed evaluation value with respect to the captured image based on a positional relationship between the reference axis and the pixel correspondence points.   
     
     
         21 . The electronic endoscope system according to  claim 20 ,
 wherein the target plane is a plane that includes an R component axis.   
     
     
         22 . The electronic endoscope system according to  claim 21 ,
 wherein the target plane is a plane that further includes a G component axis.   
     
     
         23 . The electronic endoscope system according to  claim 20 ,
 wherein the reference axis is an axis drawn on a boundary line between a region in which the pixel correspondence points are distributed and a region in which pixel correspondence points are not distributed in the target plane.   
     
     
         24 . The electronic endoscope system according to  claim 20 ,
 wherein the plotting unit plots the pixel correspondence points in a predetermined section of the target plane,   the section is defined by first and second axes that pass through the origin, and   letting the origin be a start point of the first and second axes, and other ends of the first and second axes be end points of the axes,   the axis setting unit detects a pixel correspondence point that is located on a line segment connecting the end point of the second axis and the end point of the first axis and that is closest to the end point of the second axis, and sets an axis that connects the detected pixel correspondence point and the start point as the reference axis.   
     
     
         25 . The electronic endoscope system according to  claim 20 ,
 wherein the axis setting unit partitions the target plane into a first region and a second region using the reference axis,   the evaluation value calculating unit calculates the prescribed evaluation value using pixel correspondence points plotted in the first region, and   the axis setting unit sets the reference axis in a manner according to which the number of pixel correspondence points plotted in the second region falls in a predetermined range.   
     
     
         26 . The electronic endoscope system according to  claim 20 ,
 wherein the axis setting unit sets the reference axis each time the color image is captured by an image capturing unit, or only at a predetermined timing.   
     
     
         27 . The electronic endoscope system according to  claim 20 ,
 wherein the axis setting unit calculates a provisional reference axis each time a predetermined timing is reached, and sets the reference axis based on the provisional reference axes calculated at the timings.   
     
     
         28 . The electronic endoscope system according to  claim 20 ,
 wherein the reference axis is an axis having a high correlation with a hue of a mucous membrane in a body cavity.   
     
     
         29 . The electronic endoscope system according to  claim 20 ,
 wherein the prescribed evaluation value is a numerical representation of an abnormal portion in a body cavity.   
     
     
         30 . An evaluation value calculation device comprising:
 a plotting unit configured to plot pixel correspondence points, which correspond to pixels that constitute an intracavitary color image that has a plurality of color components, on a target plane according to color components of the pixel correspondence points, the target plane intersecting an origin of a predetermined color space;   an axis setting unit configured to set a reference axis in the target plane based on pixel correspondence points plotted on the target plane; and   an evaluation value calculating unit configured to calculate a prescribed evaluation value with respect to the captured image based on a positional relationship between the reference axis and the pixel correspondence points.   
     
     
         31 . An evaluation value calculation device comprising:
 an image capturing unit configured to capture a color image that has R (Red), G (Green), and B (Blue) color components;   a plotting unit configured to plot pixel correspondence points, which correspond to pixels that constitute a captured image obtained by the image capturing unit, on a target plane according to color components of the pixel correspondence points, the target plane including a first axis that is an R component axis and a second axis that is a G component axis and is orthogonal to the first axis;   an axis setting unit configured to set a reference axis that passes through an intersection of the first axis and the second axis in the target plane and is not parallel with each of the first axis and the second axis, based on pixel correspondence points plotted on the target plane; and   an evaluation value calculating unit configured to calculate a prescribed evaluation value with respect to the captured image based on a positional relationship between the reference axis and the pixel correspondence points.   
     
     
         32 . The evaluation value calculation device according to  claim 31 ,
 wherein a start point of the first axis and a start point of the second axis are at the same location,   the axis setting unit detects a pixel correspondence point that is located on a line segment connecting an end point of the second axis and an end point of the first axis and that is closest to the end point of the second axis, and sets an axis that connects the detected pixel correspondence point and the start point as the reference axis.   
     
     
         33 . The evaluation value calculation device according to  claim 31 ,
 wherein the axis setting unit sets the reference axis each time the captured image is captured by the image capturing unit, or only at a predetermined timing.   
     
     
         34 . The evaluation value calculation device according to  claim 31 ,
 wherein the axis setting unit calculates a provisional reference axis each time a predetermined timing is reached, and sets the reference axis based on the provisional reference axes calculated at the timings.   
     
     
         35 . The evaluation value calculation device according to  claim 31 ,
 wherein the reference axis is an axis having a high correlation with a hue of a mucous membrane in a body cavity.   
     
     
         36 . The evaluation value calculation device according to  claim 31 ,
 wherein the prescribed evaluation value is a numerical representation of an abnormal portion in a body cavity.   
     
     
         37 . The evaluation value calculation device according to  claim 31 ,
 wherein the evaluation value calculation device is for incorporation in an electronic endoscope system.   
     
     
         38 . The evaluation value calculation device according to  claim 31 ,
 wherein the reference axis is an axis drawn on a boundary line between a region in which the pixel correspondence points are distributed and a region in which pixel correspondence points are not distributed in the target plane.