INTERPOLATION OF ULTRASONIC IMAGE

PURPOSE:To reduce an artifact when interpolation is performed to an ultrasonic image after the transformation from polar coordinates to orthogonal coordinates. CONSTITUTION:Three vicinal pixels constituting a triangle are extracted from an ultrasonic image after coordinates transformation in S101. Coordinates transformation is performed in S102 and three pixels are sorted for the purpose of operational simplification in S103. By this method, three pixels are arranged in a y-axis direction and the positional relation of three pixels is specified. A scanning line is set in an x-direction in S104 and interpolation on a side is performed with respect to the pixels of the crossing points of the respective sides of a triangle and the scanning line in S105 and linear interpolation is executed with respect to the pixels on the scanning line in S106. The interpolation on a side and the interpolation in the scanning line direction are repeated to apply brightness values to all of the pixels within a triangle.