Abstract: A method of generating a multiscale contrast enhanced image is described wherein the shape of edge transitions is preserved. Detail images are subjected to a conversion, the conversion function of at least one scale being adjusted for each detail pixel value according to the ratio between the combination of the enhanced center differences and the combination of the unenhanced center differences.

Abstract: The contrast of an image is enhanced by converting pixels of detail images of a multi-scale digital representation of the image according to a conversion function. The conversion function is monotonically increasing and odd and provides maximum amplification within an intermediate subrange of pixel values of a detail image which subrange is considered critical. Furthermore the slope of the conversion function has a local maximum and a local minimum.

Abstract: A digital signal representation of an image is normalized by applying a normalization parameter to all pixels of the digital signal representation of the image or to the pixels of a multi-scale representation of the image. The normalization parameter can be derived from the digital signal representation itself or from a multi-scale representation of the image. Different criteria for deriving the normalization parameter are disclosed.

Abstract: An image which has been subjected to image processing wherein contrast amplification and density can be specified independently is displayed on a display screen. The contrast of all pixels in the displayed image is changed upon movement of an indicium in a first direction and the density of all pixels in the displayed image is changed upon movement of the indicium in a second direction.

Abstract: An image which has been subjected to image processing wherein contrast amplification and density can be specified independently is displayed on a display screen. An initial density level is specified. The contrast of pixels in the displayed image having a density substantially equal to the specified initial density is changed upon movement of an indicium in a first direction and the density of pixels in the displayed image having a density substantially equal to the specified initial density is changed upon movement of the indicium in a second direction.

Abstract: A method of creating a gradation curve for gradation processing of a medical image represented by a digital signal representation to generate a gradation processed image wherein the shape of the gradation curve and signal range for which the gradation curve is defined are deduced from the digital signal representation and wherein the gradation processed image has a fixed density and fixed contrast value in a diagnostically most relevant area.

Abstract: A method of reducing noise in an image by decomposing the digital signal representation of the image into a sequence of detail images representing detail at successive scales and a residual image and modulating pixels of at least some of the detail images by applying modulating coefficients. The modulating coefficients are deduced from a single contrast-to-noise ratio image which represents the local contrast-to-noise ratio in each pixel at a predefined scale.

Abstract: A method of generating a contrast enhanced version of a grey value image by applying contrast amplification to a multiscale representation of the grey value image wherein density in the contrast enhanced version as a function of grey value and contrast amplification are specified independently.

Abstract: The contrast of an image is enhanced by converting the digital signal representation of the image according to a conversion function that is derived from a parameterized conversion function q(x) by giving specific values to the parameters of the function. Specific values for parameters that depend on the examination type to which the image relates are exclusively derived from the digital signal representation itself. No input of examination type dependent parameters is required.

Abstract: A short-time Goertzel transform is applied to the image signal to transform it into a representation of the spatial frequency component corresponding to the periodic pattern. This representation is processed. Next the inverse of the transformation is computed and the result of the inverse transformation is removed from the image signal.

Abstract: A suppression signal representing the periodic variation of a digital signal is separated into separation signals containing values of equal phase. The separations signals are subjected to high frequency attenuating filtering before being recomposed into a corrected suppression signal which is used for correcting the digital signal.

Abstract: A suppression signal representing the periodic variation of a digital signal is separated into separation signals containing values of equal phase. The separations signals are subjected to high frequency attenuating filtering before being recomposed into a corrected suppression signal which is used for correcting the digital signal.

Abstract: An image which has been subjected to image processing wherein contrast amplification and density can be specified independently is displayed on a display screen. An initial density level is specified. The contrast of pixels in the displayed image having a density substantially equal to the specified initial density is changed upon movement of an indicium in a first direction and the density of pixels in the displayed image having a density substantially equal to the specified initial density is changed upon movement of the indicium in a second direction.

Abstract: An image which has been subjected to image processing wherein contrast amplification and density can be specified independently is displayed on a display screen. The contrast of all pixels in the displayed image is changed upon movement of an indicium in a first direction and the density of all pixels in the displayed image is changed upon movement of the indicium in a second direction.

Abstract: A method of correcting artefacts in a processed digital image represented by a multi-scale gradient representation being obtained by non-linear processing of a multi-scale gradient representation of an original image. A modified gradient representation is generated by modifying gradient images of the multi-scale gradient representation of the processed image so that the directions of the gradient images are pixel-wise equal to those of the gradient images of the multi-scale gradient representation of the original image. A reconstruction algorithm is then applied to the modified gradient representation.

Abstract: A method of generating a contrast enhanced version of a grey value image by applying contrast amplification to a multiscale representation of the grey value image wherein density in the contrast enhanced version as a function of grey value and contrast amplification are specified independently.

Abstract: A digital signal representation of an image is normalised by applying a normalisation parameter to all pixels of the digital signal representation of the image or to the pixels of a multi-scale representation of the image. The normalisation parameter can be derived from the digital signal representation itself or from a multi-scale representation of the image. Different criteria for deriving the normalisation parameter are disclosed.

Abstract: A method of creating a gradation curve for gradation processing of a medical image represented by a digital signal representation to generate a gradation processed image wherein the shape of the gradation curve and signal range for which the gradation curve is defined are deduced from the digital signal representation and wherein the gradation processed image has a fixed density and fixed contrast value in a diagnostically most relevant area.

Abstract: A method of generating a contrast enhanced version of a grey value image by applying contrast amplification to a multiscale representation of the grey value image wherein density in the contrast enhanced version as a function of grey value and contrast amplification are specified independently.

Abstract: The contrast of an image is enhanced by converting pixels of detail images of a multi-scale digital representation of the image according to a conversion function. The conversion function is monotonically increasing and odd and provides maximum amplification within an intermediate subrange of pixel values of a detail image which subrange is considered critical. Furthermore the slope of the conversion function has a local maximum and a local minimum.