Abstract: The present disclosure is directed to a direct-light generator for sun-sky-imitating illumination devices configured for generating natural light similar to that from the sun and the sky The generator includes a first emitting surface and an array of light-emitting devices configured to generate from a primary light a direct light which exits the first emitting surface along a direct-light direction. The direct light exiting the first emitting surface has a luminance profile which has a narrow peak in the angular distribution around the direct-light direction and is uniform across the first emitting surface. Each light-emitting device includes a light emitter having an emitting surface and at least a pair of collimation lenses illuminated by the light emitter.

Abstract: A computer-implemented method is for artifact correction during a reconstruction of at least one slice image from at least one projection image. The at least one projection image includes a plurality of pixels, each pixel including a pixel value. The method includes determining at least one corrected projection image based on the at least one projection image via a computing circuit; reconstructing the at least one slice image based on the at least one corrected projection image; and providing the at least one slice image. The determining includes determining an average pixel value in at least one subarea of the at least one projection image, a correction value by multiplying the average pixel value by a scatter factor, and a plurality of corrected pixel values by subtracting the correction value from the plurality of pixel values. The corrected projection image includes pixels including the plurality of corrected pixel values.

Abstract: A method for segmentation of high-contrast objects in X-ray images includes receiving an X-ray projection image through an interface. The X-ray projection image includes a plurality of pixels. An image processing processor determines, for one or more pixels of the received X-ray projection image, whether the respective pixel is a shadow pixel representing a projection mapping of a high-contrast object. High-contrast object segmentation of one or more high-contrast objects is generated for the X-ray projection image based on the shadow pixels. The determination of shadow pixels includes, for the respective pixel of the received X-ray projection image, determining a ratio of the scattered radiation intensity to be assigned to the primary radiation intensity to be assigned to the pixel, comparing the ratio with a scatter-primary threshold value, and classifying the pixel, wherein the pixel is classified as a shadow pixel if the ratio is greater than the scatter-primary threshold value.

Abstract: A method is provided for image-processing an image dataset acquired from a patient by a medical imaging apparatus, (e.g., an X-ray apparatus), wherein the image dataset includes image values associated with image points, and depicts an acquisition region of the patient containing at least one object, (e.g., a medical device), to be enhanced, which is represented by image values within an image-value interval. The method includes determining a non-linearly high-pass filtered enhancement dataset, which is confined to an image portion containing image values lying in the image-value interval. The method also includes determining a result dataset by adding to the image dataset the enhancement dataset weighted by a weighting value. The method further includes outputting the result dataset.

Abstract: A method for improving an image quality of X-ray tomograms includes generating a low-pass filtered X-ray tomogram by applying a low-pass filter to a two-dimensional X-ray tomogram. The low-pass filter is only applied to pixels with image values lying within a predetermined image value interval. A high-pass filtered X-ray tomogram is generated by subtracting the low-pass filtered X-ray tomogram from the two-dimensional X-ray tomogram. A Radon transform image is generated by calculating a Radon transform of the high-pass filtered X-ray tomogram. A modified Radon transform image is generated by modifying values of the pixels of the Radon transform image with values lying outside a predetermined value interval. A modified high-pass filtered X-ray tomogram is generated by calculating an inverse Radon transform of the modified Radon transform image. A modified X-ray tomogram is generated by the addition of the modified high-pass filtered X-ray tomogram to the low-pass filtered X-ray tomogram.

Abstract: A method for the reduction of streak artifacts in an image data set reconstructed from projection images of an X-ray device is provided. The method includes determining a first interim data set by applying a non-linear low-pass filter to pixels that satisfy a selection condition. A second non-linear, high-pass-filtered interim data set is determined by pixel-by-pixel subtraction of the first interim data set from the image data set. The second interim data set is Fourier transformed in order to obtain a spatial frequency data set. Frequency portions attributable to artifacts in the spatial frequency data set are removed, and the processed spatial frequency data set is inverse Fourier transformed, such that a third interim data set is obtained. An artifact-reduced result data set is determined by addition of the third interim data set and the first interim data set.

Abstract: A computer-implemented method is for artifact correction during a reconstruction of at least one slice image from at least one projection image. The at least one projection image includes a plurality of pixels, each pixel including a pixel value. The method includes determining at least one corrected projection image based on the at least one projection image via a computing circuit; reconstructing the at least one slice image based on the at least one corrected projection image; and providing the at least one slice image. The determining includes determining an average pixel value in at least one subarea of the at least one projection image, a correction value by multiplying the average pixel value by a scatter factor, and a plurality of corrected pixel values by subtracting the correction value from the plurality of pixel values. The corrected projection image includes pixels including the plurality of corrected pixel values.

Abstract: A kit forms a display case or a part of a display case. The kit has at least one frameless side panel with a panel front side, a panel back side, a panel edge extending between the panel front side and the panel back side and four panel corners, and at least one profile strip, which extends along the panel edge from a first of the side corners to a second of the side corners. The profile strip has a fixation section covering either the panel edge and the panel back side in an edge region, or only the panel back side in an edge region, or only the panel edge, and a holding section being subsequent to the fixation section holding a cover or bottom plate. By the kit the display case can be assembled solidly and is easily disassembled.

Abstract: A method for improving an image quality of X-ray tomograms includes generating a low-pass filtered X-ray tomogram by applying a low-pass filter to a two-dimensional X-ray tomogram. The low-pass filter is only applied to pixels with image values lying within a predetermined image value interval. A high-pass filtered X-ray tomogram is generated by subtracting the low-pass filtered X-ray tomogram from the two-dimensional X-ray tomogram. A Radon transform image is generated by calculating a Radon transform of the high-pass filtered X-ray tomogram. A modified Radon transform image is generated by modifying values of the pixels of the Radon transform image with values lying outside a predetermined value interval. A modified high-pass filtered X-ray tomogram is generated by calculating an inverse Radon transform of the modified Radon transform image. A modified X-ray tomogram is generated by the addition of the modified high-pass filtered X-ray tomogram to the low-pass filtered X-ray tomogram.

Abstract: A method and an apparatus for generating an output image from a volume data set that includes a plurality of voxels are provided. In the method, a rendered 2D image is generated from the volume data set by volume rendering. In order to generate an output image with adjusted brightness, which makes a manual readjustment of the brightness superfluous, an adjustment factor is determined based on a brightness value of pixels in the rendered 2D image. By multiplying a respective voxel brightness value of the voxels in the volume data set by the adjustment factor, a brightness-adjusted volume data set is generated. By volume rendering from the brightness-adjusted volume data set, the brightness-adjusted output image is generated.

Abstract: A kit forms a display case or a part of a display case. The kit has at least one frameless side panel with a panel front side, a panel back side, a panel edge extending between the panel front side and the panel back side and four panel corners, and at least one profile strip, which extends along the panel edge from a first of the side corners to a second of the side corners. The profile strip has a fixation section covering either the panel edge and the panel back side in an edge region, or only the panel back side in an edge region, or only the panel edge, and a holding section being subsequent to the fixation section holding a cover or bottom plate. By the kit the display case can be assembled solidly and is easily disassembled.

Abstract: A method is provided for image-processing an image dataset acquired from a patient by a medical imaging apparatus, (e.g., an X-ray apparatus), wherein the image dataset includes image values associated with image points, and depicts an acquisition region of the patient containing at least one object, (e.g., a medical device), to be enhanced, which is represented by image values within an image-value interval. The method includes determining a non-linearly high-pass filtered enhancement dataset, which is confined to an image portion containing image values lying in the image-value interval. The method also includes determining a result dataset by adding to the image dataset the enhancement dataset weighted by a weighting value. The method further includes outputting the result dataset.

Abstract: A method for the reduction of streak artifacts in an image data set reconstructed from projection images of an X-ray device is provided. The method includes determining a first interim data set by applying a non-linear low-pass filter to pixels that satisfy a selection condition. A second non-linear, high-pass-filtered interim data set is determined by pixel-by-pixel subtraction of the first interim data set from the image data set. The second interim data set is Fourier transformed in order to obtain a spatial frequency data set. Frequency portions attributable to artifacts in the spatial frequency data set are removed, and the processed spatial frequency data set is inverse Fourier transformed, such that a third interim data set is obtained. An artifact-reduced result data set is determined by addition of the third interim data set and the first interim data set.

Abstract: A method for determining a three-dimensional image dataset by an X-ray device is disclosed herein. The method includes recording projection images of an examination object from a plurality of recording angles, and reconstructing the image dataset from the projection images, wherein, for at least one examined projection image, in each case an interference condition is evaluated the fulfillment of which is dependent upon at least parts of the image data of the (respective) examined projection image and/or upon at least one parameter of the radiation source during the recording of the (respective) examined projection image and indicates that the (respective) examined projection image is a projection image with interference during the recording of which arcing has occurred in the radiation source.

Abstract: A method is for determining a transformation for image registration of a first image relative to a second image. The method includes ascertaining a test series of test elements including a test transformation and a test value, the ascertaining including ascertaining the test transformation based on a sequence of test transformations and/or based on previously ascertained test elements, transforming the first image via the ascertained test transformation, ascertaining a difference image, and ascertaining the test value of the test element based on the difference image such that the test value is a measure for an extension of a frequency distribution of values of pixels of the difference image in a direction of pixel value increase. It further includes determining a minimum test value based on test values encompassed by the test elements and determining the transformation which is the test transformation of a test element including the minimum test value.

Abstract: A method and an apparatus for generating an output image from a volume data set that includes a plurality of voxels are provided. In the method, a rendered 2D image is generated from the volume data set by volume rendering. In order to generate an output image with adjusted brightness, which makes a manual readjustment of the brightness superfluous, an adjustment factor is determined based on a brightness value of pixels in the rendered 2D image. By multiplying a respective voxel brightness value of the voxels in the volume data set by the adjustment factor, a brightness-adjusted volume data set is generated. By volume rendering from the brightness-adjusted volume data set, the brightness-adjusted output image is generated.

Abstract: A method for determining a three-dimensional image dataset by an X-ray device is disclosed herein. The method includes recording projection images of an examination object from a plurality of recording angles, and reconstructing the image dataset from the projection images, wherein, for at least one examined projection image, in each case an interference condition is evaluated the fulfillment of which is dependent upon at least parts of the image data of the (respective) examined projection image and/or upon at least one parameter of the radiation source during the recording of the (respective) examined projection image and indicates that the (respective) examined projection image is a projection image with interference during the recording of which arcing has occurred in the radiation source.

Abstract: A method is for determining a transformation for image registration of a first image relative to a second image. The method includes ascertaining a test series of test elements including a test transformation and a test value, the ascertaining including ascertaining the test transformation based on a sequence of test transformations and/or based on previously ascertained test elements, transforming the first image via the ascertained test transformation, ascertaining a difference image, and ascertaining the test value of the test element based on the difference image such that the test value is a measure for an extension of a frequency distribution of values of pixels of the difference image in a direction of pixel value increase. It further includes determining a minimum test value based on test values encompassed by the test elements and determining the transformation which is the test transformation of a test element including the minimum test value.

Abstract: A method for the reduction of artifacts based on an unequal representation of the same material classes in various locations, in particular of cupping artifacts, in a three-dimensional image data set, reconstructed from two-dimensional x-ray projection images is provided. An image datum, describing an attenuation value, is allocated respectively to a voxel, wherein at least two material class regions are located in a post-processing step, which receive, in particular, image data, which is homogeneously distributed and lies in an expected material class interval of the attenuation values, and, considering at least one characteristic of the material class regions, calculates a smooth homogenization function, which is to be applied to the image data of the entire image data set and is applied to the image data of the image data set.

Abstract: A method for the reduction of artifacts based on an unequal representation of the same material classes in various locations, in particular of cupping artifacts, in a three-dimensional image data set, reconstructed from two-dimensional x-ray projection images is provided. An image datum, describing an attenuation value, is allocated respectively to a voxel, wherein at least two material class regions are located in a post-processing step, which receive, in particular, image data, which is homogeneously distributed and lies in an expected material class interval of the attenuation values, and, considering at least one characteristic of the material class regions, calculates a smooth homogenization function, which is to be applied to the image data of the entire image data set and is applied to the image data of the image data set.