1. A medical image processing apparatus which performs image processing on a medical input image, comprising: pixel extraction means for extracting an inappropriate pixel satisfying a predetermined condition in the input image; replacing pixel information calculation means for calculating replacing information with which pixel information of the inappropriate pixel is to be replaced, based on pixel information of a predetermined region including the extracted inappropriate pixel or adjacent to the extracted inappropriate pixel; and replaced image generation means for replacing the pixel information of the inappropriate pixel in the input image with the replacing information and generating a replaced image, wherein: the input image is an RGB image; the inappropriate pixel satisfying the predetermined condition is a pixel in which a signal intensity value of an R signal is not less than a predetermined threshold value; and the pixel information comprises signal intensity values of R, G, and B signals; and wherein the replacing pixel information calculation means comprises: smoothing means for smoothing a signal intensity value of a G signal or a B signal at the extracted inappropriate pixel and calculating a smoothed signal intensity value; averaging means for obtaining a first average signal intensity value which is an average value for a signal intensity value of the R signal and a second average signal intensity value which is an average value for a signal intensity value of the G signal or the B signal, in the predetermined region adjacent to the extracted inappropriate pixel; and replacing information calculation means for calculating the replacing information based on the smoothed signal intensity value, the first average signal intensity value, and the second average signal intensity value.