Scene recognition method and system using brightness and ranging mapping

• US 20010031142A1
• Filed: 12/19/2000
• Published: 10/18/2001
• Est. Priority Date: 12/20/1999
• Status: Active Grant

• Current Assignee: Cedar Lane Technologies Inc.
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Whiteside, George D.
• Granted Patent: US 6,516,147 B2
• Time in Patent Office: Days
• US Class Current: 396/61
• CPC Class Codes: G03B 7/097 for control of both exposure time and aperture
• CPC Class Codes: G03B 7/16 in accordance with both the intensity of the flash source and the distance of the flash source from the object, e.g. in accordance with the "guide number" of the flash bulb and the focusing of the camera

Abstract

A method of controlling exposure of a scene image comprising the following steps: sensing a scene for image data; deriving values representative of a brightness map of the scene; sensing the scene for image data; deriving values representative of a range map; comparing the range map with the scene brightness map; and controlling the exposure by controlling artificial illumination upon the scene. In an alternate aspect, a system is provided for controlling exposure of a scene image comprising the following elements: at least one sensor assembly; a source of artificial illumination; and a processing means.

Claims

1. A method of controlling exposure of a scene image comprising the steps of:

(a) sensing a scene for image data including scene brightness data from at least a first set of a plurality of regions of the scene including a subject region;

(b) deriving values representative of a brightness map of the scene in accordance with scene brightness data values corresponding to each of a first set of regions;

(c) sensing the scene for image data including range data from at least a second set of regions in the scene;

(d) deriving values representative of a range map in accordance with each of the second the range to determine a subject in the scene; and

, (e) comparing the range map with the scene brightness map for determining a relationship between scene brightness and the subject brightness; and

, (f) controlling the exposure by controlling artificial illumination upon the scene, whereby a relationship of ambient and artificial illumination is generally obtained based on the relationship between scene brightness and the subject brightness.

2. The method of

claim 1

wherein said step of controlling the artificial illumination controls firing intervals of a strobe for each and every combination of the scene brightness and ranging maps.

3. The method of

claim 1

wherein one of the brightness sensing or range sensing is performed in a first sensor resolution mode and the other of the range sensing or brightness sensing is performed in a second sensor resolution mode.

4. The method of

claim 1

wherein the brightness and range sensing are performed in one resolution mode.

5. The method of

claim 1

wherein said range and brightness sensing steps are performed generally simultaneously.

6. A system of controlling exposure of a scene image, the system comprises:

at least one sensor assembly for sensing image data including scene brightness from a first set of a plurality of regions in a scene;

said sensor assembly is operable for sensing range data from a second set of genrally independent regions in the scene;

a source of artificial illumination; and

, processing means for (i) defining a brightness map of the scene in accordance with the brightness data corresponding to each of the regions in the first set of regions, (ii) defining a range map of the scene in accordance to the second set of regions to determine a subject in the scene, (iii) comparing the range map with the scene brightness map for determining a relationship between scene brightness and the subject range; and

, (iv) controlling the exposure by controlling a strobe artificial illumination upon the scene, whereby a relationship of ambient and artificial illumination is generally obtained based on the relationship between scene brightness and the subject brightness.

7. The system of

claim 6

wherein said sensor assembly includes a sensor for sensing the scene brightness and for sensing the range.

8. The system of

claim 7

wherein said sensor senses one of the scene brightness and the other of the scene ranging in a first resolution mode and said sensor senses the other of the subject range and scene brightness in a second resolution mode.

9. The system of

claim 7

wherein said sensor is operable for sensing the scene brightness and ranging in a single resolution mode.

10. The system of

claim 6

wherein said sensor assembly includes an infrared pass filter assembly that is operable in one condition to allow ambient and artificial illumination from a scene to impinge on said sensor, and in another condition allows infrared from the scene to impinge on said sensor.

11. The system of

claim 6

wherein said processing means is operable for controlling the artificial illumination by a controlling a strobe for each and every combination of the scene brightness and ranging maps.