Technique that preserves specular highlights

• US 7,525,528 B2
• Filed: 09/22/2005
• Issued: 04/28/2009
• Est. Priority Date: 11/16/2004
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Feng, Xiao-Fan
• Primary Examiner(s): Mengistu; Amare
• Assistant Examiner(s): ZHOU, HONG
• Application Number:
  US11/233,748
• Publication Number:
  US 20060103621A1
• Time in Patent Office: 1,314 Days
• Field of Search: 345/81, 345/87, 345/102, 345/690, 345/691, 345/644
• US Class Current: 345/87
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A method for displaying an image on a liquid crystal display that includes a plurality of light emitting elements and a light valve. A image signal is received and a first light emitting element is illuminated based upon a substantial maximum of a non-uniform image signal in a first region. A second light emitting element is illuminated based upon a substantial maximum of a non-uniform image signal in a second region including, where the first and second light emitting elements are simultaneously illuminated.

Claims

1. A method for displaying an image on a liquid crystal display that includes an array of a plurality of light-emitting elements and a light valve, said method comprising:

(a) receiving an said image;

(b) creating a first modification of said received image by;

(i) applying a first low-pass filter to said image to produce a first filtered image; and

(ii) sub-sampling said first filtered image at the resolution of said array of plurality of light-emitting elements;

c) creating a second modification of said image, independent from said first modification of said image, by;

(i) applying a second low-pass filter to said image, different from said first low pass filter, to produce a second low pass filtered image, said second low pass filter based on an anticipated specular pattern; and

(ii) segmenting said second low pass filtered image into a plurality of blocks, each said block associated with one of said light-emitting elements, and calculating a respective substantial maximum luminance in each said block;

(d) creating a composite of said first modification and said second modification by selecting, for each said light-emitting element, a respective one of either said substantial maximum luminance associated with said light emitting element in said second modification of said image, or a predetermined statistical measure of the sub-sampled luminance value, associated with said light-emitting element, in said first modification of said image; and

(e) using said composite to drive said array of a plurality of light-emitting elements.

2. The method of claim 1 where said first low pass filter is based on a point spread function of a diffusion screen over said array of light emitting elements.

3. The method of claim 1 where said statistical measure is twice the sub-sampled luminance value.

4. The method of claim 1 where said plurality of blocks overlap.

5. The method of claim 4 where the overlapping factor is 0.5.

6. The method of claim 1 including the step of applying a correction for crosstalk on said composite.

7. The method of claim 1 where said second low pass filter has a size that simulates that of the anticipated said specular pattern.

8. The method of claim 1 where said substantial maximum luminance associated with said light emitting element is the maximum luminance associated with said light emitting element.