Method and apparatus for determining fisheye camera shadow correction parameter

Patent metadata

Field	Value
Publication number	US-11050987-B2
Application number	US-201916296462-A
Country	US
Kind code	B2
Filing date	Mar 8, 2019
Priority date	Mar 9, 2018
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

A method for determining a fisheye camera shadow correction parameter, comprising: capturing and acquiring a raw image using a fisheye camera that is not installed in an outer housing; obtaining the raw image from the fisheye camera; performing statistics on luminance information and chrominance information in each block of the raw image; and calculating a correction parameter for the fisheye camera based on the luminance information and the chrominance information of each block.

First claim

What is claimed is:

1. A method for determining a fisheye camera shadow correction parameter, comprising:
capturing and acquiring a raw image using a fisheye camera when said fisheye camera is not installed in an outer housing;
obtaining the raw image from the fisheye camera;
performing statistics on luminance information and chrominance information in each block of the raw image; and
calculating a correction parameter for the fisheye camera based on the luminance information and the chrominance information of each block;
wherein the luminance information of each block may be an average luminance value of the block, and the chrominance information of each block may be an average chrominance value of the block;
wherein the correction parameter may comprise a luminance parameter and a chrominance parameter, the luminance parameter may be a first ratio of the average luminance value of a central block and the average luminance value of each block, and the chrominance parameter may be a second ratio of the average chrominance value of a central block and the average chrominance value of each block;
wherein the raw image is captured and acquired in an integrating sphere;
wherein the fisheye camera is disposed and secured in a middle of the integrating sphere using a jig.

2. The method of claim 1 , wherein the fisheye camera comprises two fisheye lenses and the raw image includes a first raw image corresponding to a first of the two fisheye lenses, and a second raw image corresponding to a second of the two fisheye lenses, the method further comprising:
separately obtaining the first and second raw images;
using the first raw image to calculate a correction parameter of the first fisheye lens; and
using the second raw image to separately calculate a correction parameter of the second fish eye lens.

3. The method of claim 1 , further comprising:
storing the correction parameters in the fisheye camera so that the stored correction parameters are applied when the fisheye camera captures a new image.

4. A fisheye camera shadow correction method, comprising:
capturing and acquiring a raw image using a fisheye camera that when said fisheye camera is not installed in an outer housing;
obtaining the raw image from the fisheye camera;
performing statistics on luminance information and chrominance information in each block of the raw image;
calculating a correction parameter for the fisheye camera based on the luminance information and the chrominance information of each block;
obtaining the correction parameter;
and correcting an image captured by the fisheye camera using the correction parameter;
wherein the luminance information of each block may be an average luminance value of the block, and the chrominance information of each block may be an average chrominance value of the block;
wherein the correction parameter may comprise a luminance parameter and a chrominance parameter, the luminance parameter may be a first ratio of the average luminance value of a central block and the average luminance value of each block, and the chrominance parameter may be a second ratio of the average chrominance value of a central block and the average chrominance value of each block;
wherein the raw image is captured and acquired in an integrating sphere;
wherein the fisheye camera is disposed and secured in a middle of the integrating sphere using a jig.

5. The method of claim 4 , wherein the correction parameter is stored in the fisheye camera.

6. The fisheye camera shadow correction method of claim 4 , wherein the fisheye camera comprises two fisheye lenses, the method further comprising: separately obtaining correction parameters for the two fisheye lenses.

7. A fisheye camera shadow correction parameter determination device, comprising:
a raw image obtaining module adapted to obtain a raw image from a fisheye camera, said raw image being captured and acquired when said fisheye camera is not installed in an outer housing;
a statistics module adapted to perform statistics on luminance information and chrominance information in each block of the raw image; and
a correction parameter calculation module adapted to calculate a correction parameter for the fisheye camera based on the luminance information and the chrominance information;
wherein the luminance information of each block may be an average luminance value of the block, and the chrominance information of each block may be an average chrominance value of the block;
wherein the correction parameter may comprise a luminance parameter and a chrominance parameter, the luminance parameter may be a first ratio of the average luminance value of a central block and the average luminance value of each block, and the chrominance parameter may be a second ratio of the average chrominance value of a central block and the average chrominance value of each block;
wherein the raw image is captured and acquired in an integrating sphere;
wherein the fisheye camera is disposed and secured in a middle of the integrating sphere using a jig.

8. The fisheye camera shadow correction parameter determination device of claim 7 , wherein the fisheye camera comprises two fisheye lenses configured to capture separate first and second raw images; wherein the raw image obtaining module is configured to separately obtain the first raw image and the second raw image from the two fisheye lenses; the first and second raw images for separately calculating correction parameters of the two fisheye lenses.

9. The fisheye camera shadow correction parameter determination device of claim 7 , further comprising:
a storage module adapted to store the correction parameters in the fisheye camera so that the stored correction parameters may be applied when the fisheye camera captures a new image.

10. A fisheye camera shadow correction device, comprising:
a correction parameter obtaining module adapted to obtain a correction parameter for a fisheye camera, said correction parameter being calculated and acquired by means of the following method: obtaining a raw image from the fisheye camera, said raw image being captured and acquired when said fisheye camera is not installed in an outer housing; performing statistics on the luminance information and the chrominance information in each block of said raw image; and calculating the correction parameter for said fisheye camera on the basis of the luminance information and the chrominance information of each block; and
a correction module adapted to perform correction using said correction parameter on an image captured by the fisheye camera;
wherein the luminance information of each block may be an average luminance value of the block, and the chrominance information of each block may be an average chrominance value of the block;
wherein the correction parameter may comprise a luminance parameter and a chrominance parameter, the luminance parameter may be a first ratio of the average luminance value of a central block and the average luminance value of each block, and the chrominance parameter may be a second ratio of the average chrominance value of a central block and the average chrominance value of each block;
wherein the raw image is captured and acquired in an integrating sphere;
wherein the fisheye camera is disposed and secured in a middle of the integrating sphere using a jig.

11. The fisheye camera shadow correction device of claim 10 , wherein the fisheye camera comprises two fisheye lenses and the correction parameter obtaining module is configured to separately obtain correction parameters for the two fisheye lenses.

12. The fisheye camera shadow correction device of claim 10 , wherein the fi

Assignees

• Shanghai Xiaoyi Tech Co Ltd

Inventors

• Wang Xiaomin
• Lyu Tingshan
• Huang Chixiang

Classifications

• H04N23/51

  Housings · CPC title

• H04N23/55 Primary

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• G06T7/80

  Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration · CPC title

• H04N9/77 Primary

  Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase (circuits for matrixing H04N9/67) · CPC title

• G06T2207/10024

  Color image · CPC title