Processing device for video signals
First Claim
1. Processing device for video signals, comprising:
- a memory device suitable to store discrete image elements of a video field;
a filtering device supplied by said memory device and suitable to recover errors introduced by the memory device, the filtering device comprising;
a filter having an input supplied with digital signals representative of values of a plurality of discrete image elements comprising an image element to be examined and neighboring image elements, said discrete image elements being stored in the memory device, and an output supplying digital signals representative of a filtered value of the image element to be examined;
a noise detector operating on fuzzy-logic rules having an input supplied with said digital signals representative of the plurality of values of the image elements and an output supplying a weight signal representative of a degree of erroneousness of the discrete image element to be examined, the noise detector determining said degree of erroneousness comparing the value of the image element to be examined with the values of the neighboring image elements, the noise detector comprising;
a digital subtraction determiner supplied with said digital signals representative of values of said plurality of image elements and supplying difference digital codes, each one representative of a difference between the value of the image element to be examined and the value of a respective one of the neighboring image elements;
a first determiner configured to determine which of said difference digital codes has the minimum absolute value and generating a minimum digital difference code representative of the difference digital code having the minimum absolute value; and
a soft-switch device having a first input supplied with the digital signals representative of the value of the image element to be examined, a second input supplied with the output of the filter, a third input supplied with the weight signal, and an output supplying digital signals representative of a weighted average of the output of the filter and of the digital signals representative of the value of the image element to be examined according to respective weights determined by said degree of erroneousness.
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Accused Products
Abstract
A processing device for video signals has a memory device suitable to store discrete image elements of a video field and a filtering device supplied by the memory device and suitable to recover errors introduced by the memory device. The filtering device includes a filter, noise detector means, and soft-switch means. The filter has an input supplied with digital signals representative of values of a plurality of discrete image elements and comprises an image element to be examined and neighboring image elements. The discrete image elements is stored in the memory device, and an output supplying digital signals representative of a filtered value of the image element to be examined. The noise detector means operating on fuzzy-logic rules has an input supplied with the digital signals representative of the plurality of values of the image elements and an output supplying a weight signal representative of a degree of erroneousness of the discrete image element to be examined. The noise detector circuit determines the degree of erroneousness by comparing the value of the image element to be examined with the values of the neighboring image elements. The soft-switch means has a first, second and third input and an output. The first input is supplied with the digital signals representative of the value of the image element to be examined. The second input is supplied with the output of the filter. The third input is supplied with the weight signal. The output supplies digital signals representative of a weighted average of the output of the filter and of the digital signals representative of the value of the image element to be examined according to respective weights determined by the degree of erroneousness.
13 Citations
18 Claims
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1. Processing device for video signals, comprising:
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a memory device suitable to store discrete image elements of a video field; a filtering device supplied by said memory device and suitable to recover errors introduced by the memory device, the filtering device comprising; a filter having an input supplied with digital signals representative of values of a plurality of discrete image elements comprising an image element to be examined and neighboring image elements, said discrete image elements being stored in the memory device, and an output supplying digital signals representative of a filtered value of the image element to be examined; a noise detector operating on fuzzy-logic rules having an input supplied with said digital signals representative of the plurality of values of the image elements and an output supplying a weight signal representative of a degree of erroneousness of the discrete image element to be examined, the noise detector determining said degree of erroneousness comparing the value of the image element to be examined with the values of the neighboring image elements, the noise detector comprising; a digital subtraction determiner supplied with said digital signals representative of values of said plurality of image elements and supplying difference digital codes, each one representative of a difference between the value of the image element to be examined and the value of a respective one of the neighboring image elements; a first determiner configured to determine which of said difference digital codes has the minimum absolute value and generating a minimum digital difference code representative of the difference digital code having the minimum absolute value; and a soft-switch device having a first input supplied with the digital signals representative of the value of the image element to be examined, a second input supplied with the output of the filter, a third input supplied with the weight signal, and an output supplying digital signals representative of a weighted average of the output of the filter and of the digital signals representative of the value of the image element to be examined according to respective weights determined by said degree of erroneousness. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. Processing device for video signals, comprising:
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a memory device suitable to store discrete image elements of a video field; a filtering device supplied by said memory device and suitable to recover errors introduced by the memory device, the filtering device comprising; a filter having an input supplied with digital signals representative of values of a plurality of discrete image elements comprising an image element to be examined and neighboring image elements, said discrete image elements being stored in the memory device, and an output supplying digital signals representative of a filtered value of the image element to be examined; a noise detector configured to operate on fuzzy-logic rules having an input supplied with said digital signals representative of the plurality of values of the image elements and an output supplying a weight signal representative of a degree of erroneousness of the discrete image element to be examined, the noise detector determining said degree of erroneousness comparing the value of the image element to be examined with the values of the neighboring image elements, the noise detector comprising; a first determiner supplied by the digital signals representative of values of the neighboring image elements and having a first output supplying digital signals representative of the maximum value of the neighboring image elements and a second output supplying digital signals representative the minimum value of the neighboring image elements; a second determiner supplied by said first and second output of the first determiner and by the digital signals representative of the value of the image element to be examined for detecting if the image element to be examined has a value higher than said maximum value or lower than said minimum value and having an output respectively representative of said maximum value or said minimum value; a digital subtraction determiner supplied by said second determiner and by said digital signals representative of the value of the image element to be examined and having an output representative of an absolute-value difference between the digital signals representative of the value of the image element to be examined and said output of the second means; and a fuzzy processor supplied by the output of said digital subtraction determiner and generating a fuzzy-valued signal representative of a degree of deviation of the value of the image element to be examined from said maximum value or minimum value. - View Dependent Claims (10, 11, 12, 13, 18)
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14. The method of filtering video signals comprising the steps of:
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storing a video image comprised of a plurality of pixels; interpolating a value of a current pixel based on the current pixel and a plurality of surrounding pixels, the current and surrounding pixels being selected from the plurality of pixels; determining a weighting value of the current pixel based on a degree of erroneousness of the current pixel as compared to the surrounding pixels; determining a weighted average of the current pixel based on the interpolated value of the current pixel and the determined weighting value; determining minimum and maximum values from the surrounding pixels; comparing the minimum and maximum values to the current pixel; selecting one of the minimum and maximum values based on the step of comparing; subtracting the selected minimum and maximum value from the current pixel to produce a subtracted value; applying a predetermined rule to the subtracted value to produce an initial weighted value; and correcting a sign of the initial weighted value. - View Dependent Claims (15)
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16. The method of filtering video signals comprising the steps of:
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storing a video image comprised of plurality of pixels; interpolating a value of a current pixel based on the current pixel and a plurality of surrounding pixels, the current and surrounding pixels being selected from the plurality of pixels; determining a weighting value of the current pixel based on a degree of erroneousness of the current pixel as compared to the surrounding pixels; determining a weighted average of the current pixel based on the interpolated value of the current pixel and the determined weighting value; subtracting each of the surrounding pixels from the current pixel to produce a plurality of difference values; detecting a minimum value from the difference values; applying predetermined rules to the minimum value to produce an initial weighting value; and correcting a sing of the initial weighting value. - View Dependent Claims (17)
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Specification