Television perspective effects system

• US 4,667,236 A
• Filed: 04/26/1985
• Issued: 05/19/1987
• Est. Priority Date: 04/26/1985
• Status: Expired due to Fees

• Current Assignee: Digital Services Corporation
• Original Assignee: Digital Services Corporation
• Inventors: Dresdner, Daniel
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/727,890
• Time in Patent Office: 753 Days
• Field of Search: 358/22, 358/160, 358/183, 340/727, 340/729, 364/521, 364/522
• US Class Current: 348/583
• CPC Class Codes: G06T 3/00 Geometric image transformations in the plane of the image
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

This invention employs an incremental technique for performing a perspective transformation on a planar television image. The equipment modifies the coefficients to a two by two matrix multiplier at the pixel or line rate. This allows for perspective generation along either the X or Y axis of the television screen. The invention will also provide perspective generation for rotation of the image about the Z axis in addition to the rotation about one of the X or Y axes.

Claims

1. A television special effects system to produce the illusion of perspective in an image displayed on a television screen, the system comprising means for taking and for storing in a memory pixel by pixel samples of the television signal, means for reorienting the signal information in the memory to produce a desired rotation of the television image about an axis parallel to the plane of the television screen and about another axis perpendicular to the plane of the television screen and means effective to apply incremental values by an addition function to the dimensions of the image displayed on the screen in a manner to produce foreshortening and keystoning of the image in proportion to the desired degree of rotation of the image about said axes.

2. A television special effects system to produce the illusion of perspective in an image displayed on a television screen, the system comprising means for taking and for storing in a memory pixel by pixel samples of the television signal, means for reorienting the signal information in the memory to produce a desired rotation of the television image about an axis perpendicular to the plane of the television screen, and means effective to apply incremental values by an addition function to the dimensions of the image displayed on the screen in a manner to produce foreshortening and keystoning of the image in proportion to the desired degree of rotation of the image about said axis.

3. A method of producing special effects in a television display including the steps of obtaining and storing sequentially in a memory the information contained in a television signal defining the image to be displayed, calculating an initial value and an incremental value based on the desired degree of rotation of the image about each axis, performing an incremental transformation on the stored information by adding sequentially to each bit of information to be displayed a sum equal to said initial sum serially increased by said incremental value to produce foreshortening and keystoning of the image in proportion to the desired degree of rotation of the image about any one of the three axes defining a three dimensional space, and then performing a further incremental transformation on the stored information representing the dimensions of the image by adding a value in proportion to the compression to be applied to the image to indicate its rotation about said any one of the three axes.

4. A method as set forth in claim 3 in which the calculation of initial and incremental values is performed in a central processing unit and the incremental transformation on the stored information is performed in dedicated hardware.