The x axis corresponds to the first dimension of the pixel array. N1 is the first dimension of the image. Units are pixels. The y axis corresponds to the second dimension of the pixel array. N2 is the second dimension of the image.
Units are pixels.
N1,N2 are the dimensions of the image. Units are pixels. N1,N2 are the dimensions of the image. Units are pixels. A counter-clockwise rotation of the y axis to the ellipse major axis is a positive angle.