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Seeking Prior Art on Nokia patent US6504873

Priority Date: Seeking Prior Art from before Jun 13, 1997

Analysis of a Nokia patent (US6504873) which they claim WebM infringes upon.

Groklaw did some analysis that reduced their 64 patents worldwide down to a dozen US patents. This post (in the comments of the Groklaw post) lays out the independent claims of each patent.

1 A method of filtering a received digital video picture

TL;DR Upscaling filter that averages pixels on the edge of adjacent video sub-blocks based on activity in screen.

in which said digital video picture comprises video blocks, each video block comprising a certain amount of individual video pixels each video pixel having a numerical value defining a property of the video pixel and having a certain location in the video picture, and in which video picture a first video block and a second video block located adjacent to the first video block define a boundary therebetween, the method comprising the steps of:

Frames of the video are subdivided into a grid and given a number.

selecting a first video pixel from the first video block in such a way that the first video pixel is located at the boundary in the first video block to obtain a first boundary video pixel selecting a second video pixel from the second video block in such a way that the second video pixel is located at the boundary in the second video block to obtain a second boundary video pixel,

Pixels in different sub-squares are adjacent "boundary" pixels. If the boundary is 0 then those pixels would be at -1,1

selecting a first reference video pixel in the first video block and a second reference video pixel in the second video block, the first reference video pixel and the second reference video pixel being other than the first boundary video pixel and the second boundary video pixel and the first reference video pixel and the second reference video pixel being placed closer to a central portion of each of said video blocks than the respective boundary video pixel, in such a way that the reference video pixels and the boundary video pixels are situated on a straight line, the straight line being transverse to the boundary, drawn from the first reference video pixel to the second reference video pixel, wherein the first and the second boundary video pixels are located between the first and the second reference video pixels on the straight line,

Select neighbor pixels (-2,2).

defining a linear equation, using the numerical values of the reference video pixels, the linear equation giving as a solution a numerical reference value to each boundary video pixel on said straight line

Figure out an equation that will take the neighbor pixels and produce the boundary pixels.

filtering at least one boundary video pixel by adjusting the numerical value of the at least one boundary video pixel towards the reference value of the at least one boundary video pixel.

Averaging the boundary pixels using above equation.

"of the at least one" makes this a nonsensical statement but software patents are nonsensical anyway, right?

10 A terminal device for filtering a received digital video picture,

One sentence: A device that implements the filter in claim 1.

which said digital video picture comprises video blocks, each video block comprises a certain amount of individual video pixels, each video pixel having a numerical value defining a property of the video pixel and having a certain location in the video picture, in which video picture a first video block and a second video block located adjacent the first video block define a boundary therebetween, and the terminal device comprising:

A device which filters video. Frames of the video are subdivided into a grid and given a number. Pixels in different sub-squares are adjacent "boundary" pixels. If the boundary is 0 then those pixels would be at -1,1

means for selecting a first video pixel from the first video block in such a way that the first video pixel is located at the boundary in the first video block to obtain a first boundary video pixel,

means for selecting a second video pixel from the second video block in such a way that the second video pixel is located at the boundary in the second video block to obtain a second boundary video pixel,

means for selecting a first reference video pixel in the first video block and a second reference video pixel in the second video block, the first reference video pixel and the second reference video pixel being other than the first boundary video pixel and the second boundary video pixel and the first reference video pixel and the second reference video pixel being placed closer to a central portion of each of said video blocks than the respective boundary video pixel, in such a way that the reference video pixels and the boundary video pixels are situated on a straight line, the straight line being transverse to the boundary, drawn from the first reference video pixel to the second reference video pixel, wherein the first and the second boundary video pixels are located between the first and the second reference video pixels on the straight line,

means for defining a linear equation using the numerical values of the reference video pixels, the linear equation giving as a solution a numerical reference value to each boundary video pixel on said straight line, and

means for filtering at least one boundary video pixel by adjusting the numerical value of the at least one boundary video pixel towards the reference value of the at least one boundary video pixel.

11 A terminal device according to the claim 10, wherein the receiver terminal comprises receiving means for receiving the video picture via a mobile communication network.

A mobile device that implements the filter in claim 1.

12 A filtering method according to claim 10, wherein the reference value of each boundary video pixel is computed as a function of the location of the boundary video pixel on the straight line.

13. A method of filtering a received video picture, in which

The filter in claim 1 is used based on the activity in the pixels.

a digital video picture is received, the video picture comprising video blocks, each video block comprising a certain amount of individual video pixels, each video pixel having a numerical value defining a property of the video pixel and having a certain location in the video picture, and in which video picture a first video block and a second video block located adjacent the first video block define a boundary therebetween,

a first video pixel from the first video block and a second video pixel from a second video block are selected in such a way that they are adjacent each other on the opposite sides of the boundary, and

the first video pixel and the second video pixel are filtered, wherein

a first reference video pixel is selected in the first video block and a second reference video pixel is selected in the second video block in such a way that the first reference pixel, the first video pixel, the second video pixel and the second reference pixel are situated on a straight line, perpendicular to the boundary, drawn from the first reference video pixel to the second reference video pixel,

a linear equation is defined, the linear equation giving as a solution a numerical reference value to each pixel on said straight line as a function of the location of the pixel on said straight line, and

the filtering is performed by adjusting the numerical value of the first video pixel towards its reference value, and by adjusting the numerical value of the second video pixel towards its reference value, and

further wherein a decision on whether the filtering method is used or not and for which video pixels the filtering is used is done on basis of activity inside the first video block, activity inside the second video block and activity at the boundary between the first video block and the second video block, and

wherein, the decision is based on the following equation IF activityINactivityEDGEMQUANT AND activityINTHRESHOLDIN TRUE

 in which

activityIN is the variance inside the video block one and the video block two,

activityEDGE is the variance over the edge between the adjacent video block one and video block two, and

THRESHOLDIN is a Threshold value, and

MQUANT is a quantizer value.

14 A method of filtering a received digital video picture

Applying the filter from claim one but towards more central pixels.

in which said digital video picture is coded into video blocks, each video block comprising a certain amount of individual video pixels, each of said video pixels having a numerical value defining a property of the video pixel and having a certain location in the video picture, and in which video picture, a first video block is located adjacent to a second video block to define a boundary therebetween, the method comprising the steps of:

selecting a first reference video pixel in the first video block and a second reference video pixel in the second video block, the first reference video pixel and the second reference video pixel being displaced away from said boundary towards a central portion of each of said video blocks, said reference video pixels defining a straight line of video pixels transverse to said boundary, between said first reference video pixel and said second reference video pixel, wherein said straight line includes at least a first and a second adjustment video pixel located between the first and the second reference video pixels and said boundary;

defining a linear equation representing a video pixel value reference ine transverse to said boundary, said linear equation defined relative to the change in pixel values from said first reference pixel in said first video block to said second reference pixel in said second video block;

adjusting the numerical value of said at least first and second adjustment video pixels towards said pixel value reference line according to the position of said at least first and second adjustment video pixels from said boundary

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Groklaw basically deduplicated the multiple national patent claims. The comment I listed just breaks down the individual claims and at the end of the thread was some automated prior art analysis. –  Indolering May 22 '13 at 5:08
    
I do not see much analysis at those links and the independent claims do seem very thin because only the preambles are included, not the body of the claims. This site can be a good place for getting the help you are looking for. –  George White May 22 '13 at 5:20
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1 Answer 1

This might have been anticipated by this Motorola patent EP0714587A1 A method for determining whether to intra code a video block

"ABSTRACT Whether to encode a present video block of an incoming video frame, i.e., intra code, or whether to encode the difference between the present video block of the incoming frame and a best match video block from a previously store video frame, i.e., non-intra code, is determined in a video compression system (100). First, the present video block is divided into a predetermined number of sub blocks (301). Then, an average pixel value is calculated for each sub block (302) and used along with the individual pixel values of the sub block to determine sub block deviations (303). The sub block deviations are used to compute a present video block deviation (303). The present video block deviation is then compared with an error deviation (306) that is calculated based upon the present video block pixel values and the best match video block pixel values (305). If the comparison is favorable, then the difference between the present video block and the best match video block are encoded. If the comparison is unfavorable, then the present video block is encoded."

It totally busts the second independent claim:

The sub block deviations may preferably be sent to the rate controller 114 to be used for rate control 310. The rate controller uses the sub block deviations as a measure of the spatial activity within a sub block. By using the sub block deviations from the intra/non-intra determiner 113, the rate controller 114 does not have to recalculate a spatial activity measure. Based on the spatial activity and other factors, the level of quantization used by the quantizer 103 is determined.

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I think it's close, but the patent seems to be very insistent on being a filtering method used during decoding. –  Indolering Aug 10 '13 at 22:12
    
I found this but it looks like it was published in 1998. –  Indolering Aug 10 '13 at 22:26
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