Abstract: A method of processing images in images comprising curvilinear structures comprises, in parallel, a step of filtering said images and a decision step intended to select the pixels of the images pertaining to a curvilinear structure, the method comprising, in parallel, a sub-step of estimating the direction of each image pixel, as well as a sub-step of analyzing the connectivity of neighboring pixels based on their directions at the end of the sub-step of estimating the direction of each image pixel, and a sub-step of selecting groups of pixels as a function of the result of the sub-step of analyzing the connectivity of neighboring pixels based on their directions, at the end of the step of filtering. Such a method allows selection of curvilinear structures which are fine structures such as a catheter in a medical image, or thicker structures such as a tree-like structure of blood vessels.

Abstract: An image processing method and an X-ray apparatus in which a thread-like structure represented on the background in a noisy digital original image is extracted. Original image data is acquired and reduced using a transformation operation so as to provide a reduced image. The most probable locations of guide-wire points in the reduced image are selected by selecting at each point the direction of the guide-wire which provides the best match with one of several predetermined regularly oriented directions and by probing the contrast around and in the selected directions and then probing the contrast around selected locations in the original image corresponding to the selected location of points in the reduced image. Then, the points which satisfy a contrast condition are extracted and the points which also satisfy a connectivity criterion in the reduced image are connected and these points are extracted as guide-wire points of the original image.

Abstract: A method of processing images in images comprising curvilinear structures comprises, in parallel, a step of filtering said images and a decision step intended to select the pixels of the images pertaining to a curvilinear structure, the method comprising, in parallel, a sub-step of estimating the direction of each image pixel, as well as a sub-step of analyzing the connectivity of neighboring pixels based on their directions at the end of the sub-step of estimating the direction of each image pixel, and a sub-step of selecting groups of pixels as a function of the result of the sub-step of analyzing the connectivity of neighboring pixels based on their directions, at the end of the step of filtering. Such a method allows selection of curvilinear structures which are fine structures such as a catheter in a medical image, or thicker structures such as a tree-like structure of blood vessels.

Abstract: An image processing method is provided to remove areas from an image made by x-irradiation, said areas corresponding to absorption filters in the x-ray beam. Because such filters, also known as x-ray shutters, are inserted into the x-ray beam from the outside of the x-ray beam, x-ray shutter-areas extend from the periphery of the image. Therefore, once the edge of an x-ray shutter-areas has been determined, the part of the image located between the periphery and the x-ray shutter-edge is removed. X-ray shutter-edges are determined by locating transition-points in the image having brightness-transitions having maxima of both the first and second spatial derivatives of the brightness-value. An x-ray shutter-edge is then determined by fitting a curve through the transition-points. The curve fitting is performed with the use of weight-factors that are representative of the likelihood that a transition-point is on an actual x-ray shutter-edge.

Abstract: A method of processing images in order automatically to detect key pixels (K.sub.2, K.sub.3, K.sub.4) situated on the contour of an object (LV) in an initial image (I.sub.0), and a device for implementing this method in which there is storage, in the digitized initial image (I.sub.0), of the intensity of the pixels [A.sub.0 (x,y)] and of data of regions of the object (LV), classes (C.sub.1 C.sub.m); selection of pixels of interest (PI), on the contour, inside and outside the object (LV); generation of characteristics (E.sub.1 E.sub.k) for each of the pixels of interest (PI); classification of the pixels of interest (PI) into the classes (C.sub.1 C.sub.m); and selection of the key pixels (K.sub.2, K.sub.3, K.sub.4) from corresponding classes (C.sub.2, C.sub.3, C.sub.4).