Method and device for correcting an image, particularly for occupant protection

• US 20040202380A1
• Filed: 05/12/2004
• Published: 10/14/2004
• Est. Priority Date: 03/05/2001
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Wagner, Ulrich, Kohler, Thorsten
• Granted Patent: US 7,304,680 B2
• Time in Patent Office: Days
• US Class Current: 382/275
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

A source image (S) That is distorted by camera optics is transformed into a corrected image (T) by using a tabular imaging rule. This transformation occurs directly during the reading out from the image sensor and in real-time. No, one or several target pixels in the target image (T) are assigned to each source pixel of the source image.

Claims

1. A Method A method for correcting an image, comprising:

selecting at least one predefined source pixel of a source image the gray scale value which predefined source pixel can be read under a predefined source pixel address;

mapping the predefined source pixel, using a predefined imaging rule, to at least one target pixel arranged in a target image under a predefined target pixel address; and

storing the gray scale value read under the predefined source pixel address in a memory under the predefined target pixel address.

2. The method according to claim 1, wherein

the imaging rule is executed using at least one table stored in a memory of an evaluation unit.

3. The method according to claim 1, wherein

the source image is captured through an optical system of an optical sensor.

4. The method according to claim 1, wherein

the predefined source pixel is mapped to at least one target pixel directly and/or while the source image is being read from the image sensor and/or without temporary storage and/or in real time.

5. The method according to claim 1, wherein

the source image has predefined or selected source pixels that are mapped to target pixels,

reading the source pixels of a source image from the source image cyclically,

mapping the predefined source pixels to the corresponding target pixels synchronously and/or in a fixed time sequence.

6. The method according to claim 1, wherein

reading each of the source pixels under its source pixel address,

the source pixel addresses constitute a pixel address space in which the source pixel addresses are arranged in the form of a matrix, and

reading the source pixels row-by-row moving in a direction from a lower address number to a higher address number.

7. The method according to claim 1, wherein

the source image has additional source pixels that are not mapped to target pixels.

8. The method according to claim 1, wherein

the source pixels, the source pixel addresses of which are included in at least one table, are selected for mapping to at least one target pixel.

9. The method according to claim 1, wherein

the source pixel address of a selected source pixel and a target pixel address allocated to the source pixel address are present in the at least one table,

a source pixel address is selected using a synchronously clocked source counter and an associated gray scale value is read,

a table address of the at least one table is selected using a target counter, as a result of which a selected source pixel address and the associated target pixel address are output,

the source pixel address selected by the source counter is compared with the source pixel address output by the table, and if the comparison finds the two addresses to be identical,

the gray scale value of the source pixel address is stored under the target pixel address output by the tables, and

the target counter is incremented.

10. The method according to claim 1,

the source image has an image area in which fewer source pixels are selected than in another image area.

11. The method according to claim 1, wherein

at least one selected or predefined source pixel, which is arranged at the edge of the source image, is mapped to more than one target pixel.

12. The method according to claim 1, wherein

at least one selected or predefined source pixel is mapped to more than one target pixel,

at least one of the target pixel addresses of the target pixel is determined from the source pixel address of the selected source pixel using at least one table,

the gray scale value of the selected source pixel address is stored under one of the target pixel addresses, and

the gray scale value of the selected source pixel address is stored under another of the target pixel addresses while at least one or more additional unselected source pixels are being read.

13. The method according to claim 1, wherein

a time interval is available in which at least one additional source pixel that is not mapped to a target pixel is read from the source image, where two or more of the time intervals to be arranged either with one immediately after the other or with each separated from the next, and during one or more time interval

the corresponding target pixel address of the another target pixel or pixels is determined using the at least one table or an additional tables, and

the gray scale value stored under a target pixel address is read and stored by the another of the target pixel addresses.

14. The method according to claim 1, wherein

the source image has source pixels arranged in a matrix,

the address space of the at least one table is essentially the same size as the address space of the target image,

the number of target pixels is smaller than the number of source pixels, and

the at least one table has table addresses, each of which indicates a source pixel address and a target pixel address.

15. The method according to claim 1, wherein

the gray scale values of the target pixels of the target imaged are stored in a memory of an evaluation unity.

16. The method according to claim 1, wherein

an image sensor captures an image area in an interior of the vehicles that corresponds essentially to the corresponding source image of the image sensor concerned.

17. The method according to claim 1, wherein

the gray scale values of the source pixels are transmitted to an evaluation unit, and

the at least one table is stored in a memory of the evaluation unit.

18. The method according to claim 1, wherein

an image sensor is part of an optical system that acquires range information, or part of a propagation-time-dependent system.

19. The method according to claim 1, wherein

an aperture angle of a camera system is approximately 100×

90 degrees.

20. The method according to claim 1, wherein the method is used for controlled distortion of images.

21. The method according to claim 1, wherein

the method is used in mobile telephones and/or web cameras.

22. A device for correcting an image, in an occupant protection systems, comprising a camera system capturing an image area in an interior of a vehicles, the image information captured by the camera system being processed by an evaluation unit.