Generation of 3D look-up tables for image processing devices

• US 7,916,137 B2
• Filed: 03/07/2007
• Issued: 03/29/2011
• Est. Priority Date: 03/07/2007
• Status: Active Grant

• Current Assignee: Panavision International LP (Panavision Incorporated)
• Original Assignee: Panavision International LP (Panavision Incorporated)
• Inventors: Pearman, James Bernard, Bowser, Scott Allen
• Primary Examiner(s): COUSO, YON JUNG
• Application Number:
  US11/715,772
• Publication Number:
  US 20080218508A1
• Time in Patent Office: 1,483 Days
• Field of Search: 382/162, 382/167, 345/419, 345/418, 345/589, 345/591, 345/600, 345/601, 358/1.9, 358/531, 358/504, 358/523, 358/532, 358/3.27
• US Class Current: 345/419
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2330/12 Test circuits or failure detection circuits included in a display system, as permanent part thereof
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H04N 17/02 for colour television signals
• CPC Class Codes: H04N 9/68 for controlling the amplitude of colour signals, e.g. automatic chroma control circuits H04N9/71, H04N9/73 take precedence; camera processing pipelines for controlling the colour saturation of colour signals H04N23/86

Abstract

An image processor is disclosed which is capable of automatically generating a series of test signals, running the test signals through its image processing software and hardware, and capturing the resulting output signals to automatically generate a 3D LUT that represents most or all of the imaging processing steps being performed by the image processor. No external equipment is required to generate the 3D LUT. In other embodiments, the image processor may be connected to an external image processing device, and the image processor can then automatically generate a series of test signals, run those test signals through the external image processing device, and capture the resulting output signals to automatically generate a 3D LUT that represents most of all of the image processing steps being performed by the external image processing device.

Claims

1. An apparatus for automatically generating a three-dimensional look-up table (3D LUT) representing image processing, comprising:

a digital image input for receiving digital image data;

a test signal generator configured to generate digital test patterns;

an image processor configured to perform color conversion on received image data and generate converted digital image data;

a first switch coupled for providing either the digital image data from the digital image input or the digital test patterns from the test signal generator to the image processor;

a red/green/blue (RGB) value measurement circuit coupled to the image processor and configured to measure RGB values from the converted digital image data; and

a digital image output coupled to the image processor for providing the converted digital image data to an external display.

2. The apparatus of claim 1, further comprising a digital interface coupled to the image processor for adjusting the converted digital image data as generated from the digital image data.

3. The apparatus of claim 1, further comprising an internal image processor bypass output coupled to the first switch and couplable to an external image processor for providing either the digital image data from the digital image input or the digital test patterns from the test signal generator to the external image processor.

4. The apparatus of claim 3, further comprising:

an internal image processor bypass input; and

a second switch coupled for providing either converted digital image data from the external image processor or converted digital image data from the internal image processor to the RGB value measurement circuit and the digital image output.

5. The apparatus of claim 1, further comprising a memory element coupled to the RGB value measurement circuit for storing the measured RGB values from the RGB value measurement circuit.

6. The apparatus of claim 1, the test signal generator comprising a frame store and the RGB value measurement circuit comprising a memory device, wherein the frame store and the memory device are coupled to a digital interface for receiving input test patterns from and providing measured RGB values to an external computer.

7. The apparatus of claim 1, further comprising a digital video camera coupled to the digital image input and a display coupled to the digital image output.

8. The apparatus of claim 2, further comprising a computer coupled to the digital interface.

9. The apparatus of claim 4, further comprising a digital interface coupled to the image processor for adjusting the converted digital image data as generated from the digital image data, a computer coupled to the digital interface, and an external image processor coupled to the internal image processor bypass output and the internal image processor bypass input.

10. A method for automatically generating a three-dimensional look-up table (3D LUT) representing image processing, comprising:

generating digital test patterns within a unitary image processing apparatus;

performing color conversion on the digital test patterns and generating converted digital image data;

measuring red/green/blue (RGB) values from the converted digital image data within the unitary image processing apparatus; and

generating a 3D LUT based on the measured RGB values.

11. The method of claim 10, further comprising:

performing the color conversion on the digital test patterns and generating the converted digital image data using an image processor internal to the unitary image processing apparatus.

12. The method of claim 11, wherein prior to the steps of generating digital test patterns, performing color conversion, generating converted digital image data, and measuring RGB values, the method further comprises:

receiving digital image data, performing color conversion on the digital image data, and adjusting the color conversion on the digital image data, all within the unitary image processing apparatus.

13. The method of claim 12, further comprising:

performing the color conversion on either the digital test patterns or the received digital image data by switching between the digital image data and the digital test patterns within the unitary image processing apparatus.

14. The method of claim 11, further comprising controlling the color conversion using an external computer coupled to the unitary image processing apparatus.

15. The method of claim 10, further comprising:

performing the color conversion on the digital test patterns and generating the converted digital image data using an external image processor coupled to the unitary image processing apparatus.

16. The method of claim 15, further comprising:

measuring the RGB values from the converted digital image data from either the external image processor or an image processor internal to the unitary image processing apparatus by switching between the external image processor and the internal image processor.

17. The method of claim 10, further comprising storing the measured RGB values into a memory element.

18. The method of claim 10, further comprising:

generating the digital test patterns from a frame store within the unitary image processing apparatus, the frame store receiving the digital test patterns from an external computer; and

measuring the RGB values from the converted digital image data by first capturing the RGB values into a memory device and providing the measured RGB values to the external computer.

19. The method of claim 12, further comprising providing the digital image data from a digital video camera, and adjusting the color conversion on the digital image data using a display.

20. An apparatus for automatically generating a three-dimensional look-up table (3D LUT) representing image processing, comprising:

means for generating digital test patterns within a unitary image processing apparatus;

means for performing color conversion on the digital test patterns and generating converted digital image data;

means for measuring red/green/blue (RGB) values from the converted digital image data within the unitary image processing apparatus; and

means for generating a 3D LUT based on the measured RGB values.