US4752828A — Method for producing a geometrical transformation…

Claim 1

Independent Claim 273 words

A method for producing a geometrical transformation on a video image designated as an initial image, comprising the steps of: identifying each point of the initial image by a plurality of first coordinates (X, Y, O) in a first cartesian reference frame which is designated as a movable reference frame and is related to the initial image; representing each point of the initial image by a digital word; storing the digital words representing each point of the initial image at a plurality of addressable locations in a storage device having address inputs and a data output, so that a digital word corresponding to the each point and having coordinates (X, Y, O) in the initial image is delivered when address values corresponding to the each point are applied to the storage device address inputs; performing a transformation of the initial image using predetermined tranformation parameters to yield a transformed image; identifying each point of the transformed image by a plurality of second coordinates (X 3 , Y 3 , O) in a second cartesian reference frame which is related to the transformed image and is designated as a fixed reference frame; determining a relationship between the second coordinates and the first coordinates, based on the transformation parameters and calculating one computed address value; and representing each point of the transformed image by a digital word supplied from the storage device by applying computed address values to the address inputs of said storage device, said computed values being computed as a sum of the computed address value of second coordinates (X 3 , Y 3 , O) of said point and, an increment value.

Claim 2

Independent Claim 273 words

A method for producing a geometrical transformation on a video image designated as an initial image, comprising the steps of: identifying each point of the initial image by a plurality of first coordinates (X, Y, O) in a first cartesian reference frame which is designated as a movable reference frame and is related to the initial image; representing each point of the initial image by a digital word; storing the digital words representing each point of the initial image at a plurality of addressable locations in a storage device having address inputs and a data output, so that a digital word corresponding to the each point and having coordinates (X, Y, O) in the initial image is delivered when address values corresponding to the each point are applied to the storage device address inputs; performing a transformation of the initial image using predetermined tranformation parameters to yield a transformed image; identifying each point of the transformed image by a plurality of second coordinates (X 3 , Y 3 , O) in a second cartesian reference frame which is related to the transformed image and is designated as a fixed reference frame; determining a relationship between the second coordinates and the first coordinates, based on the transformation parameters and calculating one computed address value; and representing each point of the transformed image by a digital word supplied from the storage device by applying computed address values to the address inputs of said storage device, said computed values being computed as a sum of the computed address value of second coordinates (X 3 , Y 3 , O) of said point and, an increment value.

Claim 3

Dependent Claim 291 words

A method of transformation according to claim 1, wherein the geometrical transformation is an affine transformation having coefficients (A x , A y ) and includes a rotation through an angle α, both transformations being performed in the plane of the initial image, said transformation also including a projection in perspective on the plane of the transformed image, this projection being defined by a direction of view and a vanishing point, said direction of view being defined by two predetermined angular values β and γ and said vanishing point of said projection being located at a distance ρ PF from the origin of the fixed reference frame, said origin being the first point of the first line of the transformed image, and said transformation further including a translation (X O3 , Y O3 ) in the plane of the transformed image, comprising the further steps of: computing the read addresses as a function of those computed in the immediately preceding point in the transformed image when the each point in the transformed image has coordinates (X 3 >O, Y 3 O,O) said computing being in accordance with the formulae: X(X.sub.3, Y.sub.3)=X(X.sub.3 -1, Y.sub.3)+k.D.sub.xx Y(X.sub.3, Y.sub.3)=Y(X.sub.3 -1, Y.sub.3)+k.D.sub.yx ( 15) initializing values of the each point having coordinates (X 3 =O, Y 3 > O,O) and which are located at the beginning of a line of the transformed image by the values: X(O, Y.sub.3)=X(O, Y.sub.3 -1)+k.D.sub.xy Y(O, Y.sub.3)=Y(O, Y.sub.3 -1)+k.D.sub.yy ( 16) where X(O, Y 3 -1), Y(O, Y 3 -1) being the read address values computed in respect of the first point of the immediately preceding line in the transformed image; and calculating the first point of the transformed image (X 3 =O, Y 3 =O) according to the relation: ##EQU11##

Claim 4

Dependent Claim 20 words

A method according to claim 2, wherein the vanishing point is assumed to be located at infinity, and wherein k=1.

Claim 5

Dependent Claim 116 words

A method according to claim 3 for producing an effect of multiplication of the initial image in addition to the geometrical transformation in the transformed image, wherein said method comprises the further steps of: periodically reinitializing the value of (X, Y) in accordance with the formulae: X(O, Y.sub.3)=X(O, Y.sub.3 -1)+k.D.sub.xy Y(O, Y.sub.3)=Y(O, Y.sub.3 -1)+k.D.sub.yy ( 16) during each transformed-image line scan, with a period being a submultiple of the line scanning interval; periodically reinitializing the value of (X, Y) in accordance with the formulae: X(O,O)=-k.D.sub.xx.X.sub.O3 -k.D.sub.xy.Y.sub.O3 X(O,O)=-k.D.sub.yx.X.sub.O3 -k.D.sub.yy.Y.sub.O3 ( 17) during each transformed-image field scan, with a period being longer than the duration of one line scan and being a submultiple of the field scanning interval.

Claim 6

Dependent Claim 113 words

A method according to claim 4 for producing a mirror effect in addition to the geometrical transformation and the multiplication effect, and comprising the further steps of: reversing the sign of D xx and D yx at the time of each reinitialization of (X, Y) with the values given by the formulae: X(O, Y.sub.3)=X(O, Y.sub.3 -1)+k.D.sub.xy Y(O, Y.sub.3)=Y(O, Y.sub.3 -1)+k.D.sub.yy ( 16) in order to obtain symmetries with respect to vertical axes; reversing the sign of D yy and D xy at the time of each reinitialization of (X, Y) with the values given by the formula X(O,O)=-k.D.sub.xx.X.sub.O3 -k.D.sub.xy.Y.sub.O3 X(O,O)=-k.D.sub.yx.X.sub.O3 -k.D.sub.yy.Y.sub.O3 ( 17) in order to obtain symmetries with respect to horizontal axes.

Claim 7

Independent Claim 145 words

A method for producing a geometrical transformation of an initial video image, comprising the steps of: identifying each point of the video image by a first address in a first coordinate system; storing a digital word representing characteristics with each point in the video image at the first address; performing a transformation of the original image using predetermined transformation parameters to yield a transformed image; identifying each point in the transformed image by a second address in a second coordinate system; computing a value of an initial point in the transformed image; determining a first recurrence, which when added to a value of an adjacent point yields a value of a current point; determining each value of each point from the value of an adjacent point; and using such value as an address to access the stored digital word representing the characteristics of each point.

Claim 8

Independent Claim 145 words

A method for producing a geometrical transformation of an initial video image, comprising the steps of: identifying each point of the video image by a first address in a first coordinate system; storing a digital word representing characteristics with each point in the video image at the first address; performing a transformation of the original image using predetermined transformation parameters to yield a transformed image; identifying each point in the transformed image by a second address in a second coordinate system; computing a value of an initial point in the transformed image; determining a first recurrence, which when added to a value of an adjacent point yields a value of a current point; determining each value of each point from the value of an adjacent point; and using such value as an address to access the stored digital word representing the characteristics of each point.

Claim 9

Dependent Claim 55 words

A method as in claim 6 wherein said determining a recurrence step includes the steps of: determining a first recurrence between any point and a point adjacent to such any point on a same line; and determining a second recurrence between a point at the end of one line and a point on another line.

Claim 10

Dependent Claim 28 words

A method as in claim 7 wherein said computing a value of an initial point step is performed during a time interval which elapses between two successive images.

Claim 11

Dependent Claim 24 words

A method as in claim 8 wherein said geometrical transformation includes a rotation, an affine transformation and a projection to produce a perspective effect.

Claim 12

Independent Claim 125 words

An apparatus for performing a transformation on a video image, comprising: image memory means for storing a digital word representing characteristics of each point of an initial image; processing means for: (1) determining initial values for a point of a transformed image, and (2) determining a recurrence value between each point and an adjacent point of the transformed image; and adding means for producing a current address from an adjacent address by adding said recurrence value and one of (a) said initial value when said initial value is said adjacent address, and (b) the previous current address output by said adding means to thereby perform an adding operation between a recurrence value and the previous address used to produce a current address in real time.

Claim 13

Independent Claim 125 words

An apparatus for performing a transformation on a video image, comprising: image memory means for storing a digital word representing characteristics of each point of an initial image; processing means for: (1) determining initial values for a point of a transformed image, and (2) determining a recurrence value between each point and an adjacent point of the transformed image; and adding means for producing a current address from an adjacent address by adding said recurrence value and one of (a) said initial value when said initial value is said adjacent address, and (b) the previous current address output by said adding means to thereby perform an adding operation between a recurrence value and the previous address used to produce a current address in real time.

Claim 14

Dependent Claim 47 words

Apparatus as in claim 10 wherein there are two recurrence values, a first recurrence value for calculating adjacent points which are on the same line, and a second recurrence value for calculating the value of another point based on a point which is on a different line.

Claim 15

Dependent Claim 40 words

Apparatus as in claim 11 further comprising means for multiplexing said initial values and said previous current address so that one of said initial values and said previous current address is applied to a first input of said adding means.

Claim 16

Dependent Claim 79 words

Apparatus as in claim 12 further comprising first register means coupled between an output of said processing means and a second input of said adding means for temporarily storing information output by said processing means; and second register means coupled between an output of said processing means and an input of said multiplex means for temporarily storing said initial values output by said processiog means and for providing said initial values at an output thereof to said multiplex means.

Claim 17

Dependent Claim 28 words

Apparatus as in claim 10 wherein said processing means is also for (3) controlling said multiplex means so that a proper input is coupled to said adding means.

Claim 18

Dependent Claim 39 words

Apparatus as in claim 14 wherein said adding means and said multiplex means are for one component of each point of the video image and wherein there are second adding means and second multiplex means for another component thereof.

Claim 19

Dependent Claim 129 words

A device according to claim 10 in which the initial video image is any desired image, further comprising: at least one counter for generating write address values at the point scanning frequency; wherein the image memory means is a memory having a capacity equal to one image, alternately written at an address supplied by the counters and read at an address supplied by the processing means at the point scanning frequency, the written data being the value of a digitized video signal corresponding to one field of the initial image and the read values being such as to constitute the values of a video signal corresponding to one field of the transformed initial image as a result of the geometrical transformation thereby resulting in an efficiency of operational transformation.

Claim 20

Dependent Claim 31 words

A device according to claim 10 further comprising means for generating control signals for a variable-gain video switcher, wherein the image memory means is for storing data defining a geometric figure.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-06-21	1991-12-21	1992-06-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-06-21	1995-12-21	1996-06-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-06-21	1999-12-21	2000-06-21	$7700.00	Window Closed / Lapsed

Method for producing a geometrical transformation on a video image and devices for carrying out said method

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