title: A new method for distortion correction of electronic endoscope images.
abstract: A new method to correct the barrel distortion of an electronic endoscope image is presented. A correction model assuming circularly symmetric distortion is introduced with the following model parameters: the center of distortion and the coefficients of polynomials representing the distortion correction in the radial direction. If the imaging system is distortion-free, straight lines in the object space should be imaged as straight lines. Based on this criterion, a distorted image of a standard pattern consisting of a grid of several straight lines is recorded, and the model parameters are then estimated as a basis for straightening distorted lines. This method has the advantage of not needing a careful placement of the standard pattern for calibration. Correction results are presented for the grid pattern chart to verify a sufficient degree of correction. Examples of distortion correction of real intestinal images and physicians' comments are also presented.
authors.affiliation: Dept. of Inf. & Comput. Sci., Chiba Univ.
authors.forename: H
authors.initials: H
authors.lastname: Haneishi
authors.forename: Y
authors.initials: Y
authors.lastname: Yagihashi
authors.forename: Y
authors.initials: Y
authors.lastname: Miyake