Abstract: A method for improving endoscope images of, in part, fluorescent tissue regions which are illuminated with background light, which images are recorded by a color video camera wherein the color pixels from the endoscope images are transformed from the color space of the video camera (3) into a color space in which a straight line which passes through the color space region of the fluorescent light and the color space region of the background light runs parallel to a coordinate axis describing the fluorescent component of the pixels, and in that, in this color space, the fluorescent component of the pixels is changed by a non-linear characteristic which at least in regions increases the fluorescent contrast, namely the difference between higher fluorescent values and lower fluorescent values, and in that, finally, the pixels are transformed into a color space suitable for imaging.

Abstract: The present invention relates to an image reconstruction device and a corresponding method for reconstructing a 3D image of an object (7) from projection data of said object (7).

Abstract: The invention relates to a method improving the images in an image processing unit (5) receiving images from an electronic color video camera (3) of a medical endoscope (1) and then transmitting them to an image display unit (7), and to an endoscope operating on the basis of the said method, where first the pixels of the color components (RGB) are individually mapped into a color space (HSL) wherein the color saturation (S) is independent of the other components (H, L), thereupon the saturation component (S) of each pixel to be mapped is converted by means of a nonlinear mapping function (11) which amplifies the color saturation differential between an upper zone (b->1) and a lower zone (0-b) of the color saturation, lastly the pixels being remapped into an (RGB) color space suitable for image display.

Abstract: During catheter or guide wire intervention, a road map of, for example, the coronary vessel tree based on pre-interventional angiograms is displayed. This road map, however, is naturally static and hence not consistent with the instantaneous heart and respiration cycles in the life image, which may be displayed on the screen next to the road map. According to an exemplary embodiment of the present invention, images of a series of x-ray images of an object of interest are determined, where the object of interest is not sufficiently filled with the contrast agent. Advantageously, these images may be used to provide for an improved road map.

Abstract: The invention relates to a method of determining a corresponding image of a moving object for a reference image from an image sequence which represents the motion as a sequence of states of motion. To this end, two motion signals, representing the development of the relevant motions, are examined for similarities. Using the similarity function thus obtained, that image in the image sequence can be determined which represents at least approximately the state of motion of the object which is represented in the reference image. Furthermore, the invention relates to a system which is suitable for carrying out the method as well as to a computer program and a computer program product enabling a data processing unit to carry out the method.

Abstract: This invention relates to an apparatus and method for improved display of small dark structures such as in particular coronary blood vessels in digital X-ray images. A live image (S) is initially subjected to multiscale decomposition in which firstly multiple uses of low pass filtering with subsequent resolution reduction (RED), and secondly resolution increases using subsequent low pass filtration (EXP), give detailed images (D1, D2, D3, D4) of different resolution. In accordance with the first variant of the method, a mask (M) representative of the uninteresting image background is subtracted from the detailed image (D4) having the lowest degree of resolution. This ensures that the subtraction will only comprise correspondingly coarse structures with dimensions greater than the expected image motion. A further improvement can be achieved by applying a motion estimation (MOT EST) and motion compensation (MOT COMP) to the mask (M) and to the detailed image (D4) of the lowest degree of resolution.

Abstract: This invention relates to an apparatus and method for improved display of small dark structures such as in particular coronary blood vessels in digital X-ray images. A live image (S) is initially subjected to multiscale decomposition in which firstly multiple uses of low pass filtering with subsequent resolution reduction (RED), and secondly resolution increases using subsequent low pass filtration (EXP), give detailed images (D1, D2, D3, D4) of different resolution. In accordance with the first variant of the method, a mask (M) representative of the uninteresting image background is subtracted from the detailed image (D4) having the lowest degree of resolution. This ensures that the subtraction will only comprise correspondingly coarse structures with dimensions greater than the expected image motion. A further improvement can be achieved by applying a motion estimation (MOT EST) and motion compensation (MOT COMP) to the mask (M) and to the detailed image (D4) of the lowest degree of resolution.

Abstract: An x-ray examination apparatus comprises an x-ray source for generating an x-ray image and an image analysis system derives brightness variations from the x-ray image and derives a dose control signal dependent on said brightness variations in order to control the x-ray source. The image analysis system derives a distribution of said brightness variations and derives the dose control signal from the distribution of brightness variations. Preferably, the image analysis system is arranged to derive the brightness variations from the processed image and a histogram analysis is employed to derive the dose control signal.

Abstract: The invention relates to an image processing method in which an original image is first decomposed into a series of detail images, with each of which there is associated a respective spatial frequency range, low contrasts being enhanced before assembly of a final image from the images which are produced by the decomposition and are subsequently modified. The modification of the detail images is performed in dependence on the relevant image value as well as in dependence on the mean image value and/or the variation of the image values in a window around the relevant pixel.

Abstract: The invention discloses a method of processing an image including the steps of decomposing the image into detail images at successive resolution levels. The detail images at successive resolution levels contain image information at respective spatial scales. Filtering of detail images is carried-out in dependence on at least one subsequent detail image having a lower resolution level than the current detail image. A processed image is reconstructed from the filtered detail images.

Abstract: An image is processed taking into account the direction of a predominant structure of the image. Said predominant direction is derived from image information in the image. In particular, the covariance matrix having matrix elements depending on products of differences between pixel-values in separate directions is calculated. The eigenvectors of the covariance matrix correspond with the predominant direction of the image structure and the eigenvalues of the covariance matrix represent the strength of the structure in the image. The covariance matrix is computed locally, i.e. for separate regions in the images so as to take variations of the direction of predominant structures into account.

Abstract: In a method of processing an image the image is divided in one or more blocks. Separate blocks are spatially frequency transformed in that pixel-values of the blocks are transformed into spectral coefficients. A noise level of the image is estimated and reduced spectral coefficients are derived from spectral coefficients and the estimated noise level. Pixel-values for a processed block are synthesized from the reduced spectral coefficients and the processed blocks are assembled into a processed image. The noise level is estimated from the image information within the image. Preferably, a few parameters relating to the circumstances under which the image was acquired are also taken into account for estimating the noise level.

Abstract: An image processing method includes multi-resolution decomposition to decompose an input image into frequency-band images, which are subsequently filtered according to an order statistics filtering. Preferably, a finite impulse response median hybrid is employed. The filtered frequency-band images are synthesized to form the filtered output image.

Abstract: A method and system for detecting changes in moving images, wherein the system includes an image pick-up unit (3), an arithmetic unit (1), and a storage device (2). The image pick-up unit (3) records images by pixels. The arithmetic unit (1) files the video signals by pixels in the storage device (2). The arithmetic unit (1) calculates the change in the video signals of the blocks of the image n+1 with reference to the preceding image n. Different values are assigned to the blocks depending on whether the change is larger or smaller than a threshold, i.e., depending on whether the blocks are supposed to be treated further as changed or not changed. The threshold becomes all the lower the more adjacent blocks that have been designated as changed when compared to their thresholds.