System for reducing speckle noise

Claim 1

A method for reducing speckle noise in a video image, said video image being formed of an m×n array of pixel elements, each pixel element having a respective gray-scale value (V) associated therewith, where zero is less than or equal to V which is less than or equal to K, here K is a maximum gray-scale value, the method comprising the steps of: storing said video image in a memory by storing each of said m×n gray-scale values of corresponding pixel elements; transforming said video image by recalling said gray-scale value, V B , of each pixel element, comparing said gray-scale value V B of each pixel element with the gray-scale value, V A , of a first immediately adjacent pixel element and the gray-scale value, V C , of a second immediately adjacent pixel element opposite to said first immediately adjacent pixel element and substituting a new gray-scale value, V BN =V B +1, for said gray-scale value, V B , of the corresponding pixel element in response to at least one of the four following conditions being satisfied: (V B +2)≦V A ; V C ≧V B <V A ; V A ≧V B <V C ; (V B +2)≦V C ; and substituting said transformed video image for said video image in said memory.

Claim 2

A method for reducing speckle noise in a video image, said video image being formed of an m×n array of pixel elements, each pixel element having a respective gray-scale value (V) associated therewith, where zero is less than or equal to V which is less than or equal to K, here K is a maximum gray-scale value, the method comprising the steps of: storing said video image in a memory by storing each of said m×n gray-scale values of corresponding pixel elements; transforming said video image by recalling said gray-scale value, V B , of each pixel element, comparing said gray-scale value V B of each pixel element with the gray-scale value, V A , of a first immediately adjacent pixel element and the gray-scale value, V C , of a second immediately adjacent pixel element opposite to said first immediately adjacent pixel element and substituting a new gray-scale value, V BN =V B +1, for said gray-scale value, V B , of the corresponding pixel element in response to at least one of the four following conditions being satisfied: (V B +2)≦V A ; V C ≧V B <V A ; V A ≧V B <V C ; (V B +2)≦V C ; and substituting said transformed video image for said video image in said memory.

Claim 9

A method for reducing speckle noise in a video image, said video image being formed of an m×n array of pixel elements, each pixel element having a respective gray-scale value (V) associated therewith, where 0≦V≦K, where K is a maximum gray-scale value, the method comprising the steps of: storing said video image in a memory by storing each of said m×n gray-scale values of corresponding pixel elements; transforming said video image by recalling said gray-scale value, V B , of each pixel element, comparing said gray-scale value V B of each pixel element with the gray-scale value, V A , of a first immediately adjacent pixel element and the gray-scale value, V C , of a second immediately adjacent pixel element opposite to said first immediately adjacent pixel element and substituting a new gray-scale value, V BN for said gray-scale value, V B , of the corresponding pixel element in response to at least one of the four following conditions: if (V B +I)<V A , then set V BN equal to the minimum of (V A -I) and (V B +I); if V B <V A and V B <(V C +I), then set V BN equal to the minimum of V A , (V B +I) and (V C +I); if V B <V C and V B <(V A +I), then set V BN equal to the minimum of V C , (V B +I) and (V A +I); and if (V B +I) <V C , then set V BN equal to the minimum of (V C -I) and (V B +I) where I is a predetermined constant, 0<I; substituting said transformed video image for said video image in said memory.

Claim 10

A method for reducing speckle noise in a video image, said video image being formed of an m×n array of pixel elements, each pixel element having a respective gray-scale value (V) associated therewith, where 0≦V≦K, where K is a maximum gray-scale value, the method comprising the steps of: storing said video image in a memory by storing each of said m×n gray-scale values of corresponding pixel elements; transforming said video image by recalling said gray-scale value, V B , of each pixel element, comparing said gray-scale value V B of each pixel element with the gray-scale value, V A , of a first immediately adjacent pixel element and the gray-scale value, V C , of a second immediately adjacent pixel element opposite to said first immediately adjacent pixel element and substituting a new gray-scale value, V BN for said gray-scale value, V B , of the corresponding pixel element in response to at least one of the four following conditions: if (V B +I)<V A , then set V BN equal to the minimum of (V A -I) and (V B +I); if V B <V A and V B <(V C +I), then set V BN equal to the minimum of V A , (V B +I) and (V C +I); if V B <V C and V B <(V A +I), then set V BN equal to the minimum of V C , (V B +I) and (V A +I); and if (V B +I) <V C , then set V BN equal to the minimum of (V C -I) and (V B +I) where I is a predetermined constant, 0<I; substituting said transformed video image for said video image in said memory.

Claim 17

A method for reducing speckle noise in a video image, said video image being formed of an m×n array of pixel elements, each such pixel element having a respective gray-scale value V associated therewith, the method comprising the steps of: forming said video image into a binary three dimensional contour map having horizontal axes corresponding to said m×n array of pixel elements and having a vertical axis corresponding to the gray-scale values, each element in said binary three dimensional contour map being a "0" except elements corresponding to the gray-scale value of said each pixel element within said m×n array of pixel elements being a "1"; forming a first umbra from said binary three dimensional contour map by changing all elements of said binary binary dimensional contour map below an element having a value of "1" into a value of "1"; transforming said first umbra into a second umbra via a hulling process by dividing said first umbra into a plurality of first umbra vertical planes, each first umbra vertical plane including a line of adjacent elements corresponding to a line of adjacent pixel elements of said m×n array of pixel elements, transforming each of said first umbra vertical planes into a transformed first umbra vertical plane via a hulling process by changing elements having values of "0" to values of "1" if the immediately adjacent elements have one of a predetermined set of values, and forming said second umbra by assembly of said transformed first umbra vertical planes; transforming said second umbra into a third umbra by changing the value of each element of said second umbra having a value "1" to a value of "0" and changing the value of each element having a value of "0" to a value of "1"; transforming said third umbra into a fourth umbra via a complementary hulling process by dividing said third umbra into a plurality of third umbra vertical planes, each third umbra vertical plane including a line of adjacent elements corresonding to a line of adjacent pixel elements of said m×n array of pixel elements, transforming each of said third umbra vertical planes into a transformed third umbra vertical plane via a complementary hulling process by changing elements having values of "1" to values of "0" if the immediately adjacent elements have one of a predetermined set of values complementary to said predetermined set of values of said hulling process, and forming said fourth umbra by assembly of said transformed third umbra vertical planes; transforming said fourth umbra into a fifth umbra by changing the value of each element of said fourth umbra having a value "1" to a value of "0" and changing the value of each element having a value of "0" to a value of "1"; forming a transformed video image from said fifth umbra by setting the gray-scale value of each pixel element of said m×n array of pixel elements equal to the height of the highest element having a value "1" of said fifth umbra having a corresponding location on said horizontal axes; and replacing said video image with said transformed video image.

Claim 18

A method for reducing speckle noise in a video image, said video image being formed of an m×n array of pixel elements, each such pixel element having a respective gray-scale value V associated therewith, the method comprising the steps of: forming said video image into a binary three dimensional contour map having horizontal axes corresponding to said m×n array of pixel elements and having a vertical axis corresponding to the gray-scale values, each element in said binary three dimensional contour map being a "0" except elements corresponding to the gray-scale value of said each pixel element within said m×n array of pixel elements being a "1"; forming a first umbra from said binary three dimensional contour map by changing all elements of said binary binary dimensional contour map below an element having a value of "1" into a value of "1"; transforming said first umbra into a second umbra via a hulling process by dividing said first umbra into a plurality of first umbra vertical planes, each first umbra vertical plane including a line of adjacent elements corresponding to a line of adjacent pixel elements of said m×n array of pixel elements, transforming each of said first umbra vertical planes into a transformed first umbra vertical plane via a hulling process by changing elements having values of "0" to values of "1" if the immediately adjacent elements have one of a predetermined set of values, and forming said second umbra by assembly of said transformed first umbra vertical planes; transforming said second umbra into a third umbra by changing the value of each element of said second umbra having a value "1" to a value of "0" and changing the value of each element having a value of "0" to a value of "1"; transforming said third umbra into a fourth umbra via a complementary hulling process by dividing said third umbra into a plurality of third umbra vertical planes, each third umbra vertical plane including a line of adjacent elements corresonding to a line of adjacent pixel elements of said m×n array of pixel elements, transforming each of said third umbra vertical planes into a transformed third umbra vertical plane via a complementary hulling process by changing elements having values of "1" to values of "0" if the immediately adjacent elements have one of a predetermined set of values complementary to said predetermined set of values of said hulling process, and forming said fourth umbra by assembly of said transformed third umbra vertical planes; transforming said fourth umbra into a fifth umbra by changing the value of each element of said fourth umbra having a value "1" to a value of "0" and changing the value of each element having a value of "0" to a value of "1"; forming a transformed video image from said fifth umbra by setting the gray-scale value of each pixel element of said m×n array of pixel elements equal to the height of the highest element having a value "1" of said fifth umbra having a corresponding location on said horizontal axes; and replacing said video image with said transformed video image.