BURROWS-WHEELER BASED STRESS PROFILE COMPRESSION

• US 20200135095A1
• Filed: 03/04/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Mobasher, Amin
• Granted Patent: US 10,803,791 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/046 Dealing with screen burn-in prevention or compensation of the effects thereof
• CPC Class Codes: G09G 2320/048 using evaluation of the usage time
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: H03M 7/3068 Precoding preceding compression, e.g. Burrows-Wheeler transformation
• CPC Class Codes: H03M 7/70 Type of the data to be coded, other than image and sound
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/174 the region being a slice, e.g. a line of blocks or a group of blocks
• CPC Class Codes: H04N 19/60 using transform coding

Abstract

A method of stress compensation in a display includes converting a stress profile for a slice of the display from a first format to a second format based on a conversion ratio; transforming the converted stress profile for the slice of the display, with a first transformation, to form a compressed transformed stress profile; decompressing the compressed transformed stress profile to form a decompressed transformed stress profile; and transforming the decompressed transformed stress profile, with a second transformation, to form a decompressed stress profile, the second transformation being an inverse of the first transformation.

Claims

1. A method of stress compensation in a display, the method comprising:

converting a stress profile for a slice of the display from a first format to a second format based on a conversion ratio;

transforming the converted stress profile for the slice of the display, with a first transformation, to form a compressed transformed stress profile;

decompressing the compressed transformed stress profile to form a decompressed transformed stress profile; and

transforming the decompressed transformed stress profile, with a second transformation, to form a decompressed stress profile, the second transformation being an inverse of the first transformation.

2. The method of claim 1, wherein converting the stress profile for the slice of the display comprises:

dividing each slice into a plurality of sub-slices; and

converting each element of content of each sub-slice from the first format to the second format to generate the converted stress profile, wherein in the first format, each element of each sub-slice is a 32 bit number, and in the second format, each element of each sub-slice is divided into four separate bytes, each byte containing 8 bits, wherein the conversion ratio is four to one.

3. The method of claim 2, wherein the first transformation is Burrows-Wheeler transform (BWT) and the second transformation is inverse BWT.

4. The method of claim 3, wherein the BWT is applied on each element of each sub-slice after each element of each sub-slice is divided into four separate bytes, each byte containing 8 bits, to generate a transformed stress profile of the slice of the display.

5. The method of claim 4, wherein a data compression algorithm is applied on the transformed stress profile of the slice to generate the compressed transformed stress profile.

6. The method of claim 5, wherein the data compression algorithm is bzip2.

7. The method of claim 4, wherein transforming the converted stress profile for the slice of the display further comprising:

permuting elements of the transformed stress profile of the slice of the display, with a first permutation, to form a permuted transformed stress profile; and

compressing the permuted transformed stress profile to form the compressed transformed stress profile.

8. The method of claim 7, wherein transforming the decompressed transformed stress profile comprising:

permuting elements of the decompressed transformed stress profile of the display, with a second permutation, wherein the second permutation is an inverse of the first permutation.

9. The method of claim 7, wherein the first permutation is a circular shift by a constant amount.

10. The method of claim 7, wherein the first permutation is a circular shift by a pseudorandom amount.

11. The method of claim 7, wherein the first permutation is a circular shift.

12. The method of claim 11, wherein transforming the decompressed transformed stress profile, with the second transformation, to form the decompressed stress profile, is based on permuting the elements of the decompressed transformed stress profile of the display.

13. The method of claim 1, further comprising:

storing the compressed transformed stress profile in a memory.

14. A system for performing stress compensation in a display, the system comprising:

a memory; and

a processing circuit configured to;

convert a stress profile for a slice of the display from a first format to a second format based on a conversion ratio;

transform the converted stress profile for the slice of the display, with a first transformation, to form a compressed transformed stress profile;

decompress the compressed transformed stress profile to form a decompressed transformed stress profile; and

transform the decompressed transformed stress profile, with a second transformation, to form a decompressed stress profile, the second transformation being an inverse of the first transformation.

15. The system of claim 14, wherein the processing circuit is further configured to:

divide each slice into a plurality of sub-slices; and

convert each element of content of each sub-slice from the first format to the second format to generate the converted stress profile, wherein in the first format, each element of each sub-slice is a 32 bit number, and in the second format, each element of each sub-slice is divided into four separate bytes, each byte containing 8 bits, wherein the conversion ratio is four to one.

16. The system of claim 15, wherein the first transformation is Burrows-Wheeler transform (BWT) and the second transformation is inverse BWT, and wherein the BWT is applied on each element of each sub-slice after each element of each sub-slice is divided into four separate bytes, each byte containing 8 bits, to generate a transformed stress profile of the slice of the display.

17. The system of claim 16, wherein a data compression algorithm is applied on the transformed stress profile of the slice to generate the compressed transformed stress profile.

18. The system of claim 16, wherein the processing circuit is further configured to:

permute elements of the transformed stress profile of the slice of the display, with a first permutation, to form a permuted transformed stress profile; and

compress the permuted transformed stress profile to form the compressed transformed stress profile.

19. A display, comprising:

a display panel;

a memory; and

a processing circuit configured to;

convert a stress profile for a slice of the display from a first format to a second format based on a conversion ratio;

transform the converted stress profile for the slice of the display, with a first transformation, to form a compressed transformed stress profile;

decompress the compressed transformed stress profile to form a decompressed transformed stress profile; and

transform the decompressed transformed stress profile, with a second transformation, to form a decompressed stress profile, the second transformation being an inverse of the first transformation.

20. The display of claim 19, wherein the processing circuit is further configured to:

divide each slice into a plurality of sub-slices; and

convert each element of content of each sub-slice from the first format to the second format to generate the converted stress profile, wherein in the first format, each element of each sub-slice is a 32 bit number, and in the second format, each element of each sub-slice is divided into four separate bytes, each byte containing 8 bits, wherein the conversion ratio is four to one, wherein the first transformation is Burrows-Wheeler transform (BWT) and the second transformation is inverse BWT, and wherein the BWT is applied on each element of each sub-slice after each element of each sub-slice is divided into four separate bytes, each byte containing 8 bits, to generate a transformed stress profile of the slice of the display.