Image adjustment with tone rendering curve

• US 20050123193A1
• Filed: 12/05/2003
• Published: 06/09/2005
• Est. Priority Date: 12/05/2003
• Status: Abandoned Application

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Lamberg, Markku, Bjorknas, Kristina, Vuori, Tero, Oja, Joni
• Application Number:
  US10/729,872
• Publication Number:
  US 20050123193A1
• Time in Patent Office: Days
• US Class Current: 382/167
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• 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: G09G 5/10 Intensity circuits
• CPC Class Codes: H04N 1/4074 using histograms

Abstract

The invention relates to a method for rendering images on display devices with improved quality. To allow adjusting luminance values of pixels depending on image information, it is proposed that contents of said image are analysed at least partially, a tone rendering curve based on said analysed image content is determined and luminance values of pixels within said image are adjusted according to said determined tone rendering curve.

Claims

1. A method for rendering images on display devices with improved quality with the steps of:

analysing at least partially contents of said image determining a tone rendering curve based on said analysed image content, and

adjusting luminance values of pixels within said image according to said determined tone rendering curve.

2. The method of claim 1, wherein luminance values of pixels are analysed for determining said tone rendering curve.

3. The method of claim 1, wherein an image histogram is analysed for determining said tone rendering curve.

4. The method of claim 1, wherein at least two different tone rendering curves are stored, and wherein said determined tone rendering curve is taken from said storage.

5. The method of claim 1, wherein said tone rendering curve is customized according to properties of said display device.

6. The method of claim 1, wherein said tone rendering curve is applied to said luminance values of pixels within an HSV or Lsα

colour space.

7. The method of claim 1, wherein ambient light information is acquired, and wherein said tone rendering curve is also determined based on said ambient light information.

10. A display device for presenting images to viewers according to a method of claim 1, said display device comprising:

a screen for showing said image,

image analysing means for analysing at least partially contents of said image,

tone rendering curve determination means for determining a tone rendering curve based on said analysed image content, and

image adjusting means for adjusting luminance values of pixels within said image according to said determined tone rendering curve.

11. A display device for presenting images to viewers according to a method of claim 1, said display device comprising:

a screen for showing said image,

ambient light acquisition means for acquiring ambient light information,

tone rendering curve determination means for determining a tone rendering curve based on said acquired ambient light information, and

image adjusting means for adjusting luminance values of pixels within said image according to said determined tone rendering curve.

12. A display device for presenting images to viewers according to a method of claim 1, said display device comprising:

a screen for showing said image,

image analysing means for analysing at least partially contents of said image,

ambient light acquisition means for acquiring ambient light information,

tone rendering curve determination means for determining a tone rendering curve based on said analysed image content, and said acquired ambient light information, and

image adjusting means for adjusting luminance values of pixels within said image according to said determined tone rendering curve.

13. A display device driver for driving a display device according to claim 10, comprising:

image analysing means for analysing image content,

tone rendering curve determination means for determining a tone rendering curve based on said analysed image content, and

image adjusting means for adjusting luminance values of pixels within said image according to said acquired tone rendering curve.

14. A system for presenting images with improved quality to viewers, comprising:

a display device according to claim 10, and an ambient light sensor for providing ambient light information,

wherein said display device adjusts luminance values of pixels within said image according to a rendering curve determined at least partially by said ambient light information.

15. A computer program for driving a display device, or a display device driver, operable to cause a processor to perform a method according to claim 1.

16. A computer program product with a computer program according to claim 15 tangibly stored thereon.

8. A method for rendering images on display devices with improved quality with the steps of:

acquiring ambient light information,

analysing said ambient light information,

determining a tone rendering curve based on said ambient light information, and

adjusting luminance values of pixels within said image according to said determined tone rendering curve.

9. A method for rendering images on display devices with improved quality with the steps of:

analysing at least partially contents of said image,

acquiring ambient light information,

determining a tone rendering curve based on said ambient light information, and said image content, and

adjusting luminance values of pixels within said image according to said determined tone rendering curve.