Abstract: A method for detecting an ellipsoid includes: extracting an ellipsoid candidate; extracting an ellipsoid contour; calculating an ellipsoid parameter; calculating an adaptability ratio; and eliminating the ellipsoid candidate. Extracting the ellipsoid candidate includes: inputting an image with figures; selecting the ellipsoid candidate from the figures; and extracting a contour candidate point and a center point. Extracting the ellipsoid contour includes: drawing straight lines; determining contour candidate points; calculating first and second distances; and defining ellipsoid contour points. Calculating the ellipsoid parameter is based on the ellipsoid contour points and the center point. Calculating the adaptability ratio includes: drawing a complete ellipsoid; and calculating the adaptability ratio between the complete ellipsoid and the ellipsoid candidate. Eliminating the ellipsoid candidate is performed when the adaptability ratio is equal to or smaller than a threshold.

Abstract: A heat exchanger such as a condenser for use in an automobile air-conditioning system is composed of a pair of header tanks, plural tubes connecting both header tanks, and fins made of a thin aluminum plate disposed between the tubes. Those components are all connected to one another by brazing to form a unitary body of the heat exchanger. A solder material for bonding the tubes and the header tanks is attached onto the inner surface of both header tanks to prevent the solder material from dispersing into the thin fins in the brazing process. Thus, the thin aluminum fins are protected against erosion due to the solder dispersed therein.