US7151844B2 — Image sensor method and apparatus having hardware…

Claim 1

Independent Claim 255 words

A method for detecting edges in an image using an image sensor that comprises a two-dimensional array of addressable pixels, with each of said pixels providing a data value indicative of a portion of the image sensed by that pixel, the method comprising the steps of: (a) sensing the image using the image sensor; and (b) carrying out the following steps for each of a number of selected pixels using a two-dimensional localized group of pixels surrounding each selected pixel, wherein each of the localized groups of pixels comprises a plurality of one-dimensional sets of pixels, each one-dimensional set being orthogonally offset from the other one-dimensional sets in the group: (b1) accessing a one-dimensional set of pixels contained within the localized group of pixels; (b2) reading the data values associated with the pixels accessed in step (b1); (b3) determining an intermediate data value using a smoothing function that is applied to the data values read in step (b2); (b4) repeating steps (b1) through (b3) for each of the one-dimensional sets of pixels contained within the localized group to thereby produce a set of said intermediate data values; and (b5) determining a final data value for the selected pixel using a differencing function that is applied to the set of intermediate data values; wherein step (b) further comprises processing the selected pixels sequentially such that, for each selected pixel, steps (b1) through (b5) are carried out for that selected pixel prior to carrying out any of the steps (b1) through (b5) for the next selected pixel.

Claim 2

Independent Claim 255 words

A method for detecting edges in an image using an image sensor that comprises a two-dimensional array of addressable pixels, with each of said pixels providing a data value indicative of a portion of the image sensed by that pixel, the method comprising the steps of: (a) sensing the image using the image sensor; and (b) carrying out the following steps for each of a number of selected pixels using a two-dimensional localized group of pixels surrounding each selected pixel, wherein each of the localized groups of pixels comprises a plurality of one-dimensional sets of pixels, each one-dimensional set being orthogonally offset from the other one-dimensional sets in the group: (b1) accessing a one-dimensional set of pixels contained within the localized group of pixels; (b2) reading the data values associated with the pixels accessed in step (b1); (b3) determining an intermediate data value using a smoothing function that is applied to the data values read in step (b2); (b4) repeating steps (b1) through (b3) for each of the one-dimensional sets of pixels contained within the localized group to thereby produce a set of said intermediate data values; and (b5) determining a final data value for the selected pixel using a differencing function that is applied to the set of intermediate data values; wherein step (b) further comprises processing the selected pixels sequentially such that, for each selected pixel, steps (b1) through (b5) are carried out for that selected pixel prior to carrying out any of the steps (b1) through (b5) for the next selected pixel.

Claim 3

Dependent Claim 47 words

The method of claim 1 , wherein step (b) further comprises detecting edges in a first one of the dimensions of said array and wherein the one-dimensional set of pixels used in step (b1) comprises a set of pixels extending in the second dimension of said array.

Claim 4

Dependent Claim 154 words

The method of claim 2 , further comprising to step of(c) detecting edges in the second dimension of said array by carrying out the following steps for each of a number of selected pixels using a localized group of pixels surrounding each selected pixel: (c1) accessing a one-dimensional set of pixels that are contained within the localized group of pixels and that extend in the first dimension; (c2) reading the data values associated with the pixels accessed in step (c1); (c3) determining an intermediate data value using a smoothing function that is applied to the data values read in step (c2); (c4) repeating steps (c1) through (c3) for each of the one-dimensional sets of pixels contained within the localized group to thereby produce a set of said intermediate data values; (c5) determining a final data value for the selected pixel using a differencing function that is applied to the set of intermediate data values.

Claim 5

Dependent Claim 15 words

The method of claim 1 , wherein said smoothing function comprises a one-dimensional Gaussian function.

Claim 6

Dependent Claim 17 words

The method of claim 1 , wherein said differencing function comprises a one-dimensional, first derivative Gaussian function.

Claim 7

Dependent Claim 51 words

The method of claim 1 , wherein the smoothing function comprises a set of weights and wherein step (b3) further comprises: determining a number of multiplication products by multiplying each data value wit an associated one of said weights, and determining the intermediate data value by summing together the multiplication products.

Claim 8

Dependent Claim 27 words

The method of claim 1 , further comprising carrying out steps (b1) through (b5) using hardwired circuitry formed on a single chip that includes the image sensor.

Claim 9

Dependent Claim 62 words

The method of claim 1 , wherein step (a) further comprises sensing and recording the image using an image sensor having a non-destructive readout, and wherein step (b) further comprises carrying out steps (b1) through (b5) for each of a number of adjacent pixels, whereby the data value recorded by at least some of said pixels is read out more than once.

Claim 10

Dependent Claim 39 words

The method of claim 1 , wherein step (b) further comprises carrying out steps (b1) through (b5) by buffering of at least some of said intermediate data values and without buffering of the data values read in step (b2).

Claim 11

Dependent Claim 132 words

An image sensor for use in sensing an image and outputting image data that identifies edges contained within the image, comprising: an array of addressable pixels, each of which provides a non-destructive readout of an analog signal indicative of a portion of the image sensed by that pixel; and an edge detection circuit comprising: a smoothing filter circuit connected to said array, said smoothing filter circuit having an output for supplying filtered output data and having one or more inputs for receiving a plurality of the analog signals from said pixels; and a differencing filter circuit having an input coupled to the output of said smoothing filter circuit to receive the filtered output data, said differencing filter circuit having an output for supplying image data that identifies edges contained within the image.

Claim 12

Dependent Claim 132 words

An image sensor for use in sensing an image and outputting image data that identifies edges contained within the image, comprising: an array of addressable pixels, each of which provides a non-destructive readout of an analog signal indicative of a portion of the image sensed by that pixel; and an edge detection circuit comprising: a smoothing filter circuit connected to said array, said smoothing filter circuit having an output for supplying filtered output data and having one or more inputs for receiving a plurality of the analog signals from said pixels; and a differencing filter circuit having an input coupled to the output of said smoothing filter circuit to receive the filtered output data, said differencing filter circuit having an output for supplying image data that identifies edges contained within the image.

Claim 13

Dependent Claim 24 words

An image sensor as defined in claim 10 , wherein at least one of said filter circuits comprises one or more switched-capacitor multiplying circuits.

Claim 14

Dependent Claim 54 words

An image sensor as defined in claim 11 , wherein said smoothing filter circuit includes n switched-capacitor multiplying circuits, each of which has an input connected to said array to simultaneous receive n analog signals from n different pixels in said array, and wherein said switched-capacitor multiplying circuits include one or more binary weights.

Claim 15

Dependent Claim 33 words

An image sensor as defined in claim 10 , wherein said differencing filter circuit includes a plurality of buffers for temporary storage of the filtered output data provided by said smoothing filter circuit.

Claim 16

Dependent Claim 45 words

An image sensor as defined in claim 10 , wherein said smoothing filter circuit is connected to said array via a multiplexor circuit that accesses different sets of pixels from said array and provides the analog signals from the accessed pixels to said smoothing filter.

Claim 17

Dependent Claim 46 words

An image sensor as defined in claim 10 , wherein said edge detection circuit comprises a horizontal edge detection circuit having a plurality of said inputs connected to said array to simultaneously receive analog signals from different pixels located in any single row of said array.

Claim 18

Dependent Claim 67 words

An image sensor as defined in claim 15 , further comprising a control circuit connected to said array to provide said horizontal edge detection circuit with analog signals from different groups of contiguous pixels located within any single row of said array and to sequentially provide said horizontal edge detection circuit with analog signals from the same group of pixels located within contiguous rows of said array.

Claim 19

Dependent Claim 43 words

An image sensor as defined in claim 15 , further comprising a vertical edge detection circuit having a second plurality of said inputs connected to said array to simultaneously receive analog signals from different pixels located in any single column of said array.

Claim 20

Dependent Claim 124 words

An image sensor as defined in claim 17 , further comprising a control circuit connected to said array to provide said horizontal edge detection circuit with analog signals from different groups of contiguous pixels located within any single row of said array and to sequentially provide said horizontal edge detection circuit with analog signals from the same group of pixels located within contiguous rows of said array; and wherein said control circuit is further operable to provide said vertical edge detection circuit with analog signals from different groups of contiguous pixels located within any single column of said array and to sequentially provide said vertical edge detection circuit with analog signals from the same group of pixels located within contiguous columns of said array.

Claim 21

Dependent Claim 70 words

An image sensor as defined in claim 10 , further comprising a control circuit for selectively providing analog signals from different pixels to said smoothing filter, wherein said smoothing filter circuit and said differencing filter circuit together comprise a mask and wherein said control circuit is operable to convolve said mask with said array to thereby output the image data for each of number of different pixels in said array.

Claim 22

Dependent Claim 22 words

An image sensor as defined in claim 10 , wherein said array and edge detection circuit together comprise a single integrated circuit.

Claim 23

Dependent Claim 19 words

An image sensor as defined in claim 10 , wherein said smoothing filter circuit comprises a one-dimensional Gaussian filter.

Claim 24

Dependent Claim 21 words

An image sensor as defined in claim 21 , wherein said differencing filter circuit comprises a one-dimensional, first derivative Gaussian filter.

Claim 25

Independent Claim 126 words

A method for detecting edges in an image using an image sensor that comprises a two-dimensional array of pixels, with each of said pixels providing a data value indicative of a portion of the image sensed by that pixel, the method comprising the steps of: providing a mask that comprises a one-dimensional Gaussian function applied to groups of the image data values in a first direction to thereby produce intermediate data values that each represent a combination of the image data values contained in one of said groups, said mask further comprising a separate one-dimensional, first derivative Gaussian function applied to sets of the intermediate data values; and convolving the mask with the image to produce edge data for each of a number of selected pixels.

Claim 26

Independent Claim 126 words

A method for detecting edges in an image using an image sensor that comprises a two-dimensional array of pixels, with each of said pixels providing a data value indicative of a portion of the image sensed by that pixel, the method comprising the steps of: providing a mask that comprises a one-dimensional Gaussian function applied to groups of the image data values in a first direction to thereby produce intermediate data values that each represent a combination of the image data values contained in one of said groups, said mask further comprising a separate one-dimensional, first derivative Gaussian function applied to sets of the intermediate data values; and convolving the mask with the image to produce edge data for each of a number of selected pixels.

Claim 27

Dependent Claim 98 words

The method of claim 23 , further comprising the steps of: providing a second mask that comprises a one-dimensional Gaussian function applied to additional groups of the image data values in the second direction to thereby produce additional intermediate data values that each represent a combination of the image data values contained in one of said additional groups, said mask further comprising a separate one-dimensional, first derivative Gaussian function applied to sets of the additional intermediate data values: and convolving the second mask with the image to produce edge data for each of a number of selected pixels.

Claim 28

Dependent Claim 27 words

The method of claim 24 , further comprising the step of combining together the edge data obtained as a result of convolving the first and second masks.

Claim 29

Dependent Claim 36 words

The method of claim 24 , further comprising carrying out each of the steps using an image sensor having a non-destructive readout and using hardwired circuitry formed on a single chip that includes the image sensor.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2009-12-18	2010-06-19	2010-12-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2013-12-18	2014-06-19	2014-12-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2017-12-18	2018-06-19	2018-12-19	$7700.00	Window Closed / Lapsed

Image sensor method and apparatus having hardware implemented edge detection processing

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