Overprinting accuracy analysis algorithm for multi-color printings

A new algorithm for overprinting accuracy analysis of multi-color printings is presented by applying image processing technology and color separation technology to quality inspection of multi-color printings. The standard image and the images collected from printings are color-separated, then each pair of images with the same color is matched; finally overprinting error is obtained by applying the inherent information embodied in inspected images and image registration data. With the new algorithm it is unnecessary to print color marks on the margin of printing media. So additional operations, such as margin-cutting are unnecessary. The experiment shows that the algorithm has accuracy and efficiency higher than traditional methods. Thus it can satisfy the requirement of precise printings.