Abstract: In a method of picture signal enhancement, a picture signal is subjected (3, 7) to a histogram-based picture signal modification based on a luminance level distribution over a whole picture or a first part of the picture, and the histogram-based picture signal modification is locally adjusted (5) in dependence on locally measured picture signal properties other than contrast and brightness, the locally measured picture signal relating to second parts of the picture that are each substantially smaller than the whole picture or the first part of the picture, the second parts being within the whole picture or the first part of the picture. Preferably, the second parts are individual pixels.

Abstract: An image processing apparatus (100) for improving images comprising a classification unit (102) for setting classification values to various regions of the images, and an improvement unit (104) for improving the image based on the classification values of the regions. The classification unit (102) takes into account only those pixels of the image that have a color value which is substantially equal to one of the color values from a predetermined range of color values. Based on these pixels the classification unit (102) determines whether the pixels belong to texture or to flat regions by comparing 2 histograms, one taking into account all the pixels with the color in the predetermined range of color values, the second one counting only these same pixels if their luminance value differs more than a given threshold form the luminance of their neighbor.

Abstract: In a method of detecting text in a video signal (VS), high horizontal frequencies in the video signal (VS) are detected (ED) to obtain horizontal edge detection results (refo, refpp1, refpp2), and horizontal edge detection results (refo) at a given position are correlated (C) with horizontal edge detection results (refpp1, refpp2) at vertically neighboring positions.

Abstract: In a video signal enhancement method, a video signal (Y) is histogram-based processed to obtain a histogram-processed video signal (Y′), and a sharpness of the histogram-processed video signal (Y′) is enhanced to obtain an output video signal (Y″) in dependence upon a sharpness enhancement control signal (CS) derived from at least the histogram-processed video signal (Y′). Advantageously, the sharpness enhancement control signal (CS) represents a derivative of the histogram-processed video signal (Y′).

Abstract: In a method of picture signal enhancement, a picture signal is subjected (3, 7) to a histogram-based picture signal modification based on a luminance level distribution over a whole picture or a first part of the picture, and the histogram-based picture signal modification is locally adjusted (5) in dependence on locally measured picture signal properties other than contrast and brightness, the locally measured picture signal relating to second parts of the picture that are each substantially smaller than the whole picture or the first part of the picture, the second parts being within the whole picture or the first part of the picture.

Abstract: An image processing apparatus (100) for improving images comprising a classification unit (102) for setting classification values to various regions of the images, and an improvement unit (104) for improving the image based on the classification values of the regions. The classification unit (102) takes into account only those pixels of the image that have a color value which is substantially equal to one of the color values from a predetermined range of color values. Based on these pixels the classification unit (102) determines whether the pixels belong to texture or to flat regions by comparing 2 histograms, one taking into account all the pixels with the color in the predetermined range of color values, the second one counting only these same pixels if their luminance value differs more than a given threshold form the luminance of their neighbor.

Abstract: An image processing apparatus (100) for improving images depending on the type of regions within the image, comprises a segmentation unit (102) to localize regions with a pre-selected type and an improvement unit (106) being designed to improve the image, which can be controlled in order to modulate the amount of improvement over the image. The image processing apparatus (100) further comprises a determination unit to find a range of values to characterize the pixels of the regions which should be handled separately based on the results of the segmentation unit (102).

Abstract: In a method of detecting text in a video signal (VS), high horizontal frequencies in the video signal (VS) are detected (ED) to obtain horizontal edge detection results (refo, refpp1, refpp2), and horizontal edge detection results (refo) at a given position are correlated (C) with horizontal edge detection results (refpp1, refpp2) at vertically neighboring positions.