A radiation image of an object is formed with radiation, which has passed through the object. The radiation image is then photoelectrically read out, and an image signal made up of a series of image signal components representing the radiation image is thereby obtained. Frequency processing is carried out on the image signal in accordance with a predetermined emphasis coefficient .beta.. When the frequency processing is carried out on image signal components corresponding to a peripheral region in the radiation image, which peripheral region has a predetermined width, the value of the emphasis coefficient .beta. used during the frequency processing is decreased monotonously from a value for an image signal component corresponding to a position on the radiation image, which position is closer to the middle part of the radiation image, to a value for an image signal component corresponding to a position on the radiation image, which position is closer to the exterior of the radiation image. The frequency processing is thus carried out such that an artifact occurring at peripheral regions in a reproduced visible image may become imperceptible.

A method for processing a radiographic image to obtain a processed image signal Sproc based on an original image signal Sorg. The method including the steps of: obtaining the original image signal Sorg representing the radiographic image based on radiographic image information transmitted through an object; obtaining an unsharp mask signal Sus corresponding to the original image signal Sorg; and conducting an operation presented by the formula: Sproc=A(Sorg)+B(Sus). In the formula, A(Sorg) is the function which does not include the unsharp mask signal Sus, B(Sus) is the function which does not include the original image signal Sorg.

An x-ray system acquires an initial low-contrast, wide latitude (G=2.5, or G=2 or less) x-ray image of a breast. A processing system automatically finds suspected abnormalities in the breast by processing the low contrast initial image, and then automatically converts the initial x-ray image to a high-contrast, narrow latitude image at the locations of the found abnormalities to thereby facilitate diagnosis and patient care. The technology includes effective ways to produce, process and display the various images, and can be extended to other types of images.

A filtering process is carried out on an original image, which is constituted of a lattice-like array of picture elements, that are located at predetermined intervals along the rows and columns of the lattice-like array, by using a mask having a predetermined size and with respect to each of the picture elements of the original image. The mean value of the values of picture elements falling within the mask is calculated with the filtering process, and a smoothed image represented by the thus calculated mean values is thereby obtained. The filtering process is carried out repeatedly on the smoothed image. Processing for emphasizing high frequency components of the original image is then carried out in accordance with the smoothed image, which has thereby been obtained. A processed image, in which an artifact is not perceptible, is thereby obtained.

The human-eye viewing of an image on a transparency is enhanced by adaptively modulating illumination of the transparency with an unsharp, complementary representation of the image.