This processing item searches the input image for parts having a high degree of similarity to the target circle mark (model), and measures its circle evaluated value (similarity) and position.In a normal search, image pattern models are used that look at the color and light/dark information. In EC Circle Search, however, models are used that look at the profile.Therefore, this processing assures a reliable search even for low-contrast or noisy images.It is also possible to measure the number of circles in the input image.