Apparatus for measuring quality of holographic display and hologram measurement pattern thereof

Patent metadata

Field	Value
Publication number	US-10990063-B2
Application number	US-201916552988-A
Country	US
Kind code	B2
Filing date	Aug 27, 2019
Priority date	Apr 2, 2019
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

The present description may provide a method of generating a hologram measurement pattern for measuring image quality of holographic display, including: generating a test pattern and a common pattern including at least one grayscale bar; generating measurement pattern data by combining the common pattern with a frame of the test pattern; and generating the hologram measurement pattern by inserting a random phase into the measurement pattern data and an apparatus applied thereto, thereby more accurately measuring the quality of the 3D holographic image reproduced by the holographic display.

First claim

What is claimed is:

1. A method for generating a hologram measurement pattern for measuring image quality of a holographic display, the method comprising:
generating a test pattern and a common pattern including at least one grayscale bar;
generating measurement pattern data by combining the common pattern with a frame of the test pattern; and
generating the hologram measurement pattern by inserting a random phase into the measurement pattern data.

2. The method of claim 1 , wherein
the at least one grayscale bar is one of a red grayscale bar, a green grayscale bar, a blue grayscale bar, and white grayscale bar.

3. The method of claim 1 , wherein the generating of the common pattern including at least one grayscale bar includes
assigning a three-dimensional (3D) depth value to each grayscale step of the at least one grayscale bar.

4. The method of claim 3 , wherein
the grayscale step of the at least one grayscale bar is represented by a color filled with a predetermined concentration within a rectangular area, a circle, a polygon, or a cross.

5. The method of claim 1 , wherein
the test pattern is one of a distortion evaluation test pattern, a modulation transfer function (MTF) measurement pattern, a color chart pattern, and a full-screen white pattern.

6. The method of claim 1 , wherein the generating the hologram measurement pattern by inserting a random phase into the measurement pattern data includes:
inserting the random phase into the measurement pattern data and converting the measurement pattern data in which the random phase is inserted into a hologram pattern by a computer generated hologram (CGH) generation method; and
determining a hologram pattern having a minimum difference between a hologram reconstructed image of the hologram pattern and the measurement pattern data as the hologram measurement pattern.

7. The method of claim 1 , further comprising:
converting the hologram measurement pattern into a format of a hologram image file; and
measuring quality of the holographic display by uploading the holographic image file to a spatial light modulator.

8. The method of claim 7 , wherein the converting the hologram measurement pattern into a format of a hologram image file includes
converting a real number value of a pixel of the hologram measurement pattern into an integer value by performing quantization and normalization on the hologram measurement pattern.

9. The method of claim 7 , wherein
the format of the hologram image file is one of jpg, bmp, png, tif, and tiff.

10. An apparatus for generating a hologram measurement pattern for measuring image quality of a holographic display, the apparatus comprising:
a test pattern generator configured to generate a test pattern;
a common pattern generator configured to generate a common pattern including at least two grayscale bar;
a measurement pattern combiner configured to generate measurement pattern data by combining the common pattern with a frame of the test pattern; and
a measurement pattern computer generated hologram (CGH) generator configured to generate the hologram measurement pattern by inserting a random phase into the measurement pattern data.

11. The apparatus of claim 10 , wherein
the at least two grayscale bar includes a white grayscale bar, and further includes one of a red grayscale bar, a green grayscale bar, and a blue grayscale bar.

12. The apparatus of claim 11 , wherein when the measurement pattern combiner generate the measurement pattern data, the measurement pattern combiner combines the white grayscale bar above the test pattern, and combines one of the red grayscale bar, the green grayscale bar, and the blue grayscale bar below the test pattern.

13. The apparatus of claim 10 , wherein when the common pattern generator generates the common pattern including at least one grayscale bar, the common pattern generator assigns a three-dimensional (3D) depth value to each grayscale step of the at least two grayscale bar.

14. The apparatus of claim 10 , wherein when the test pattern generator generates the test pattern, the test pattern generator generates one of a distortion evaluation test pattern, a modulation transfer function (MTF) measurement pattern, a color chart pattern, and a full-screen white pattern as the test pattern.

15. The apparatus of claim 10 , wherein the measurement pattern CGH generator includes:
a random phase inserting processor configured to insert the random phase into the measurement pattern data;
a CGH generator configured to convert the measurement pattern data in which the random phase is inserted into a hologram pattern by a computer generated hologram (CGH) generation method; and
a pattern uniformity verification processor configured to determine a hologram pattern having a minimum difference between a hologram reconstructed image of the hologram pattern and the measurement pattern data as the hologram measurement pattern.

16. An apparatus for measuring quality of a holographic display, the apparatus comprising:
a memory configured to store a program;
a processor configured to execute the program to perform:
generating measurement pattern data by combining a test pattern with a common pattern including at least one grayscale bar outside the test pattern; and
generating a hologram measurement pattern by inserting a random phase into the measurement pattern data; and

a light measurement device (LMD) configured to measure the quality of the holographic display from a hologram reconstructed image of the hologram measurement pattern.

17. The apparatus of claim 16 , wherein the processor is configured to execute the program to further perform converting a real number value of a pixel of the hologram measurement pattern into an integer value by performing quantization and normalization on the hologram measurement pattern, wherein the integer value is mapped to each pixel in an image file corresponding to the hologram measurement pattern.

18. The apparatus of claim 17 , wherein a format of the image file is one of jpg, bmp, png, tif, and tiff.

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Nam Jeho

Classifications

• G03H2001/0441

  Formation of interference pattern, not otherwise provided for · CPC title

• G03H2001/0033

  in hologrammetry for measuring or analysing · CPC title

• G03H1/0486 Primary

  Improving or monitoring the quality of the record, e.g. by compensating distortions, aberrations · CPC title

• G03H1/2294

  Addressing the hologram to an active spatial light modulator · CPC title

• G03H1/2202 Primary

  Reconstruction geometries or arrangements · CPC title