Method of displaying shot image on car reverse video system

• US 20090147085A1
• Filed: 01/29/2008
• Published: 06/11/2009
• Est. Priority Date: 12/07/2007
• Status: Active Grant

• Current Assignee: Altek Corporation
• Original Assignee: Altek Corporation
• Inventors: Liao, Kuo-Hung, Wu, Shie-Ching
• Granted Patent: US 8,218,008 B2
• Time in Patent Office: Days
• US Class Current: 348/148
• CPC Class Codes: G09G 2340/14 Solving problems related to the presentation of information to be displayed
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T

Abstract

A method of displaying a shot image on a car reverse video system is described, which is applicable for adjusting an image displaying angle of the car reverse video system with a fixed lens according to a distance from an obstacle. Firstly, a scene image behind the car is shot through using the lens. Then, a distance detector is activated to detect a distance from the obstacle behind the car. If the distance from the obstacle is smaller than a preset distance, a scaling ratio is set according to a ratio of the preset distance to the distance from the obstacle. Finally, according to the scaling ratio and a distance between each pixel in the scene image and a reference point, all pixel pitches are adjusted, such that the scene image is deformed, and thus achieving an effect of switching a viewing angle of the scene image.

Claims

1. A method of displaying a shot image on a car reverse video system, executed in a car reverse video system, for automatically calibrating a displaying angle of an image shot by a photographic lens with a fixed shooting angle, comprising:

shooting a scene image behind the car through using the lens;

activating a distance detector to detect a distance from an obstacle behind the car;

setting a scaling ratio according to an equation below, if the distance from the obstacle is smaller than a preset distance;

Scaling Ratio=Preset Distance/Distance from Obstacle; and

adjusting pixel pitches according to the scaling ratio and distances between a reference point and all pixels in the scene image, such that the scene image is deformed to achieve an effect of switching a viewing angle.

2. The method of displaying a shot image on a car reverse video system as claimed in claim 1, wherein the lens is one selected from a group consisting of a common lens, a wide angle lens, and a fisheye lens.

3. The method of displaying a shot image on a car reverse video system as claimed in claim 1, wherein the step of detecting the distance from the obstacle comprises:

activating the distance detector and sending an ultrasonic signal; and

receiving the ultrasonic signal, and calculating a distance between the obstacle and the car according to a returning time of the ultrasonic signal.

4. The method of displaying a shot image on a car reverse video system as claimed in claim 1, wherein the process of calibrating the pixel pitches in the scene image further comprises calibrating the pixel pitches from the reference point in a radial manner.

5. The method of displaying a shot image on a car reverse video system as claimed in claim 1, wherein the process of adjusting the pixel pitches of the scene image further comprises:

disposing a reference line at the scene image according to the scaling ratio;

filtering out pixels above the reference line in the scene image;

increasing the remaining pixel pitches in a manner of logarithmic scale according to a distance from the reference line;

generating a calibrated image according to the calibrated pixel pitches; and

displaying the calibrated image on a screen of the car reverse video system.