Method and device for merging images of calibration devices

• US 10,516,822 B2
• Filed: 12/29/2015
• Issued: 12/24/2019
• Est. Priority Date: 10/16/2015
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chang, Chin-Kuei, Lu, Shang-Chieh, Chiu, Wei-Yao, Jiang, Bor-Tung
• Primary Examiner(s): Cese, Kenny A
• Application Number:
  US14/982,562
• Publication Number:
  US 20170111580A1
• Time in Patent Office: 1,456 Days
• CPC Class Codes: G06K 15/027 Test patterns and calibration arrangements for controlling or analysing printing mechanisms of typewriters or selective printing units B41J29/393 takes precedence; colour correction using test pattern analysis in general H04N1/6033
• CPC Class Codes: G06T 2207/10141 Special mode during image acquisition
• CPC Class Codes: G06T 2207/20212 Image combination
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 3/4038 Image mosaicing, e.g. composing plane images from plane sub-images
• CPC Class Codes: G06T 7/337 involving reference images or patches
• CPC Class Codes: G06T 7/40 Analysis of texture depth or shape recovery from texture G06T7/529
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

The present disclosure provides an image merging method. The image merging method includes the following step. First, the calibration unit is provided, wherein a calibration device of the calibration unit includes a plurality of known characteristic information. The calibration device is captured. A conversion relationship is created. A relationship of positions of the images is analysis according to the conversion relationship. The images are formed. In additional, an image merging device is provided.

Claims

1. An image merging method, comprising the steps of:

providing a plurality of calibration devices, being arranged corresponding to different positions of an object to be inspected, wherein each of the calibration devices includes a plurality of known characteristic information;

obtaining raw images of the calibration devices respectively, wherein each of the raw images corresponds to one of the calibration devices, each of the raw images includes a plurality of image characteristic information that are corresponding to the known characteristic information of its corresponding calibration device;

establishing a conversion formula according to the known characteristic information of each of the calibration devices and the image characteristic information of the corresponding image;

performing an analysis for obtaining position relationship between the raw images according to the conversion formula, comprising;

establishing a plurality of virtual point characteristic information, wherein the virtual point characteristic information for each raw image corresponds to a plurality of virtual images outside the raw image, and the virtual images are arranged to correspond to other raw images, wherein two virtual images can be inferred from each raw image; and

comparing and obtaining position relationships between raw images that are disposed neighboring to one another according to the conversion formula by the use of the image characteristic information and the virtual point characteristic information; and

merging the raw images.

2. The image merging method of claim 1, wherein the imaging of each of the calibration devices further comprising the step of:

extracting the image characteristic information from each raw image.

3. The image merging method of claim 2, wherein the extracting of the image characteristic information further comprising the step of:

identifying linear features or corner features in the image characteristic information.

4. The image merging method of claim 2, wherein the extracting of the image characteristic information further comprising the step of:

establishing position relationships between the image characteristic information.

5. The image merging method of claim 4, wherein the establishing of the position relationships between the image characteristic information further comprising the step of:

using a character to determine positions of the image characteristic information.

6. The image merging method of claim 5, wherein the using of the character to determine positions of the image characteristic information further comprising the step of:

using markers or character symbols of a scale gage to determine positions of the image characteristic information.

7. The image merging method of claim 4, wherein the establishing of the position relationships between the image characteristic information further comprising the step of:

proceeding a texture feature analysis.

8. The image merging method of claim 7, wherein the texture feature analysis is enabled to obtain the position relationships between the image characteristic information based upon the relationships of texture features found in the image characteristic information.

9. The image merging method of claim 8, wherein the texture feature analysis further comprising the step of:

finding occurrence frequencies of a specific texture for the image characteristic information, wherein the texture features found in the image characteristic information comprise the specific texture.

10. The image merging method of claim 1, wherein the conversion formula is established by the use of an algorithm of collinearity condition equations.

11. The image merging method of claim 1, wherein after the merging of the raw images, the method further comprising the step of:

inspecting the object to be inspected.

12. An image merging device, comprising:

a plurality of calibration devices, being arranged at different positions of an object to be inspected, wherein each of the calibration devices includes a plurality of known characteristic information;

a plurality of image capturing devices, each being provided for capturing a raw image of its corresponding calibration device; and

a processing unit, coupled to the image capturing devices for receiving the raw images captured by the image capturing devices;

wherein each of the raw images includes a plurality of image characteristic information that are corresponding to the known characteristic information of its corresponding calibration device, and the processing unit is enabled to establish a conversion formula according to the known characteristic information of each of the calibration devices and the image characteristic information of the corresponding image, moreover, the processing unit is enabled to perform an analysis for obtaining position relationship between the image capturing devices and the object according to the conversion formula so as to stitch the raw images, comprising;

establishing a plurality of virtual point characteristic information, wherein the virtual point characteristic information for each raw image corresponds to a plurality of virtual images outside the raw image, and the virtual images are arranged to correspond to other raw images, wherein two virtual images can be inferred from each raw image; and

comparing and obtaining position relationships between raw images that are disposed neighboring to one another according to the conversion formula by the use of the image characteristic information and the virtual point characteristic information.

13. The image merging device of claim 12, wherein each of the calibration device further comprising:

a scale gage, being disposed at the periphery of the known characteristic information.

14. The image merging device of claim 12, wherein the known characteristic information are alternatively arranged into an array.

15. The image merging device of claim 12, wherein each of the image capturing devices is a device selected from the group consisting of:

a charge-coupled device (CCD), a complementary metal-oxide semiconductor (CMOS), a pan-tilt-zoom camera, and a digital monitor.

16. The image merging device of claim 12, wherein the processing unit uses an image processing algorithm to extract the image characteristic information respectively from each of the raw images.

17. The image merging device of claim 12, wherein the conversion formula is established by the use of an algorithm of collinearity condition equations.

18. The image merging device of claim 12, wherein each of the calibration devices is substantially a textured plane with non-specific iteration structures.

19. The image merging device of claim 12, wherein each of the known characteristic information is a shape selected from the group consisting of:

a rectangle, a square, a triangle, and a cross.

20. The image merging device of claim 12, wherein each of the known characteristic information is feature selected from the group consisting of:

a line and a character.

21. The image merging device of claim 13, wherein the scale gage is formed with markers or character symbols, and the markers or the character symbols are provided for a user to determine the coordinates of the known characteristic information and also the relative position relationships between the known characteristic information.