Camera set-up and method for ascertaining picture signals having color values

• US 8,817,140 B2
• Filed: 02/03/2010
• Issued: 08/26/2014
• Est. Priority Date: 02/24/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Simon, Stephan
• Primary Examiner(s): Haskins, Twyler
• Assistant Examiner(s): Trehan, Akshay
• Application Number:
  US12/699,472
• Publication Number:
  US 20100214455A1
• Time in Patent Office: 1,665 Days
• Field of Search: 348/272, 348/273, 348/113, 356/218, 356/121, 382/104, 340/467, 340/937, 701/36
• US Class Current: 348/273
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: G06V 10/12 Details of acquisition arrangements; Constructional details thereof
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 20/00 Scenes; Scene-specific elements control of digital cameras H04N23/60
• CPC Class Codes: G06V 20/584 of vehicle lights or traffic lights
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values

Abstract

A method for ascertaining image signals having color values and a camera set-up, which has: a camera having camera optics, an image sensor for recording an environment and for outputting first image signals, and a color mask applied in front of the image sensor, and an evaluation device, which picks up the first image signals emitted by the image sensor, the image sensor having a plurality of sensor pixels and the color mask having a plurality of filter pixels which are each situated in front of the sensor pixels and include first colored filter pixels and transparent filter pixels; and some of the sensor pixels picking up the light via the colored filter pixels and outputting the first color values, and additional sensor pixels picking up the light via the transparent filter pixels and outputting the intensity values. The evaluation device ascertains second color values from the intensity values and the first color values of various sensor pixels, and forms second image signals from the first color values and the second color values.

Claims

1. A camera set-up, comprising:

a camera having camera optics, an image sensor for recording an environment and for outputting first image signals, and a color mask applied in front of image sensor; and

an evaluation device, which picks up the first image signals emitted by the image sensor, the image sensor having a plurality of sensor pixels and the color mask having a plurality of filter pixels which are each situated in front of the sensor pixels and include first colored filter pixels and transparent filter pixels;

wherein some of the sensor pixels pick up light via the colored filter pixels and output first color values, and additional sensor pixels pick up light via the transparent filter pixels and emitting intensity values;

wherein the evaluation device ascertains second color values from the intensity values and the first color values of various sensor pixels, and ascertains second image signals from the first color values and the second color values;

wherein the evaluation device ascertains the second color value as a complementary value to the first color value, using at least one intensity value and a first color value, and an attenuation which is determined by a ratio of the first color value to the intensity value;

wherein the second color is a mix of two other colors besides the first color; and

wherein color in the second image signals is represented using the first color value and the second color value in proportion to each other.

2. The camera set-up of claim 1, wherein the first colored filter pixels are transparent only for a sub-range of the visible light, which includes a red wavelength range, and have an attenuation for other spectral ranges, and the transparent filter pixels are transparent for the entire spectral range of the visible light.

3. The camera of claim 1, wherein the color mask has only transparent filter pixels and first colored filter pixels of a single color.

4. The camera of claim 3, wherein the colored filter pixels are red filter pixels, approximately every fourth filter pixel being red and the additional filter pixels are transparent.

5. The camera set-up of claim 1, wherein the camera optics are defocussed on an object distance greater than infinity.

6. The camera set-up of claim 1, wherein the evaluation device ascertains approximation vectors, from the first color values and the second color values, each approximation vector having at least three components, which are formed from the first color values and the second color values, and the evaluation device forms the second image signals using the approximation vectors.

7. The camera set-up of claim 6, wherein each of the approximation vectors includes a first component obtained from the first color values and at least two additional components obtained from the ascertained second color values.

8. The camera set-up of claim 7, wherein the evaluation device ascertains a functional vector by scaling one of the approximation vectors using a prefactor, which is ascertained as a function of an attenuation, which is given by the ratio of a first color value to an intensity value.

9. The camera set-up of claim 6, wherein the approximation vectors are RGB vectors in which components corresponding to the two other colors are represented using the second color values.

10. The camera of claim 1, wherein the camera is a vehicle camera for recording a vehicle environment, and the evaluation device outputs the visualization vectors to be represented at least one of on an internal vehicle display device and for a vehicle assistance function.

11. The camera set-up of claim 1, wherein the evaluation device ascertains the second color value using a weighting factor that specifies a color contribution of the two other colors.

12. A method for ascertaining image signals having color values, the method comprising:

recording an environment using an image sensor, the image sensor having a plurality of sensor pixels, which pick up light via filter pixels having different transmission properties, of which the colored filter pixels let the light over a narrow wavelength range pass through, and the transparent filter pixels let the light over a wide wavelength range pass through which at least partially includes the narrow wavelength range;

ascertaining a first image signal, wherein some of the sensor pixels pick up the light via the colored filter pixels and output first color values, and additional sensor pixels pick up the light via the transparent filter pixels and output intensity values;

ascertaining second color values from the intensity values and the first color values of various sensor pixels; and

ascertaining second image signals using the first color values and the second color values;

wherein the second color value, as a complementary value to the first color value, is ascertained using at least one intensity value and a first color value, and an attenuation, which is determined by a ratio of the first color value to the intensity value;

wherein the second color is a mix of two other colors besides the first color; and

wherein color in the second image signals is represented using the first color value and the second color value in proportion to each other.

13. The method of claim 12, wherein approximation vectors are ascertained from the first color values and the second color values, each approximation vector having at least three components, which are formed from the first color values and the second color values, and the second image signals are formed using the approximation vectors.

14. The method of claim 13, wherein each of the approximation vectors includes a first component obtained from the first color values and at least two additional components obtained from the ascertained second color values.

15. The method of claim 14, wherein a functional vector is ascertained by scaling one of the approximation vectors using a prefactor, which is ascertained as a function of an attenuation, which is given by the ratio of a first color value to an intensity value.

16. The method of claim 13, wherein the approximation vectors are RGB vectors in which components corresponding to the two other colors are represented using the second color values.

17. The method of claim 12, wherein the first color values and the intensity values of adjacent sensor pixels are used to ascertain the second color values.

18. The method of claim 12, wherein the second color value is ascertained using a weighting factor that specifies a color contribution of the two other colors.

19. A method for ascertaining image signals having color values, the method comprising:

recording an environment using an image sensor, the image sensor having a plurality of sensor pixels, which pick up light via filter pixels having different transmission properties, of which colored filter pixels let the light over a narrow wavelength range pass through, and transparent filter pixels let the light over a wide wavelength range pass through which at least partially includes the narrow wavelength range;

ascertaining a first image signal, wherein some of the sensor pixels pick up the light via the colored filter pixels and output first color values, and additional sensor pixels pick up the light via the transparent filter pixels and output intensity values;

ascertaining second color values from the intensity values and the first color values of various sensor pixels; and

ascertaining second image signals using the first color values and the second color values;

wherein approximation vectors are ascertained from the first color values and the second color values, each approximation vector having at least three components, which are formed from the first color values and the second color values, and the second image signals are formed using the approximation vectors;

wherein each of the approximation vectors includes a first component obtained from the first color values and at least two additional components obtained from the ascertained second color values;

wherein a functional vector is ascertained by scaling one of the approximation vectors using a prefactor, which is ascertained as a function of an attenuation, which is given by the ratio of a first color value to an intensity value; and

wherein the second color value is ascertained from the equation