Imaging device for producing high resolution images using subpixel shifts and method of using same

• US 9,674,430 B1
• Filed: 03/09/2016
• Issued: 06/06/2017
• Est. Priority Date: 03/09/2016
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Li, Nianyi, McCloskey, Scott
• Primary Examiner(s): Frech, Karl D
• Application Number:
  US15/064,637
• Time in Patent Office: 454 Days
• Field of Search: 235375, 23546207, 23546211, 23546223, 23546224, 23546229
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06T 3/4069 by subpixel displacements
• CPC Class Codes: G06T 3/4076 using the original low-resolution images to iteratively correct the high-resolution images
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: H04N 23/683 performed by a processor, e.g. controlling the readout of an image memory
• CPC Class Codes: H04N 23/951 by using two or more images to influence resolution, frame rate or aspect ratio

Abstract

An imaging device for producing a high resolution image of a target with an imaging sensor and a method using the same is provided. The method is comprised of the steps of: determining, from the target size, resolution requirements of the image to be produced; capturing multiple individual low resolution images of the target, a minimum number of individual images captured being based upon the resolution requirements determined in the determining resolution requirements step; moving the OIS module to specific positions between the capturing of the individual low resolution images in the capturing multiple low resolution images step, the specific positions being based upon the resolution requirements in the determining resolution requirements step; and processing the multiple low resolution images to produce a high resolution image.

Claims

1. A method of producing a higher resolution image of a target with an imaging sensor associated with an optical image stabilization (OIS) module, comprising the steps of:

determining, from the target size, resolution requirements of the image to be produced;

capturing multiple individual lower resolution images of the target, a minimum number of individual images captured being based upon the resolution requirements determined in the determining resolution requirements step;

moving the OIS module to specific positions between the capturing of the individual lower resolution images in the capturing multiple lower resolution images step, the specific positions being based upon the resolution requirements in the determining resolution requirements step; and

processing the multiple lower resolution images to produce a higher resolution image by producing a blurred image with super resolution of the target from the captured multiple lower resolution images and de-blurring the blurred higher resolution image to generate a higher resolution image.

2. The method of claim 1, wherein the resolution requirements include resolution magnitude and direction.

3. The method of claim 1, wherein the captured lower resolution images are composed of pixels, and wherein each pixel in the de-blurred higher resolution image has at least one corresponding pixel in the lower resolution images.

4. The method of claim 1, further comprising the step of determining a matrix for a set of linear equations which models the blurred higher resolution image based upon the step of determining resolution limits and wherein the de-blurring step is accomplished by applying and solving the set of linear equations.

5. The method of claim 4, wherein the de-blurring matrix is a Gaussian kernel.

6. The method of claim 1, wherein the de-blurring step is accomplished by the steps of:

applying a Fourier transform to the blurred image with super resolution;

multiplying the Fourier Transform in the frequency domain; and

applying an inverse of the Fourier Transform to the product of multiplying in order to generate the higher resolution image.

7. The method of claim 1, wherein the step of processing the multiple lower resolution images to produce a higher resolution image is accomplished by applying a back projection algorithm to the multiple lower resolution images.

8. The method of claim 1, wherein the captured lower resolution images are composed of pixels;

and the step of determining resolution requirements of the image to be produced includes determining number and shift locations of the OIS such that all pixels in the blurred higher resolution image correspond to at least one pixel in the lower resolution images.

9. The method of claim 7, wherein the step of applying a back-projection algorithm includes incorporating prior information on the target in the processing to resolve ambiguities.

10. The method of claim 1, wherein the step of determining resolution requirements involves the steps of:

recognizing barcode symbologies and determining the number of pixels in each direction needed for decoding.

11. The method of claim 10, further comprising the step of sending the higher resolution image to a decoder.

12. A device, comprising:

an imaging sensor;

an optical image stabilization (OIS) module, the imaging sensor and the OIS module being associated; and

a processor communicatively linked to the OIS module and the imaging sensor;

the processor being configured to determine resolution requirements of the image to be produced from the target size;

the processor being further configured to instruct the imaging sensor how many lower resolution images should be captured based upon the resolution requirements;

the imaging sensor being configured to capture multiple images of the target based upon the instructions from the processor;

the processor being further configured to determine movement of the OIS module to specific positions while the imaging sensor is capturing multiple images based upon the determined resolution requirements of the image and to communicate the determined movement to the OIS module;

the OIS module being configured to move to the specific determined positions based upon the communications from the processor while the imaging sensor is capturing multiple images of the target, the OIS module moving between the determined positions between image captures by the imaging sensor; and

the processor is configured to produce a blurred image with super resolution of the target from the captured multiple lower resolution images and is configured to de-blur the blurred higher resolution image in processing the multiple lower resolution images to produce a higher resolution image.

13. The device of claim 12, wherein the processor is configured to use spatial domain de-blurring with a system of linear equations to process the multiple lower resolution images to produce a higher resolution image.

14. The device of claim 12, wherein the resolution requirements include resolution magnitude and direction.

15. The device of claim 12, wherein the captured lower resolution images are composed of pixels;

and wherein the number of lower resolution images captured and the determined positions of the OIS module are sufficient such that all pixels in the processed multiple lower resolution images correspond to at least one pixel in the captured lower resolution images.

16. The device of claim 12, the processor is configured to apply an algorithm selected from linear equations, Fourier transforms, and back-projection algorithms to the blurred image with super resolution of the target in de-blurring the blurred higher resolution image.

17. The device of claim 16, wherein the processor is further configured to determine a matrix for a set of linear equations which models the blurred higher resolution image based upon the determined resolution requirements.

18. The device of claim 12, wherein the processor is configured to apply an algorithm selected from linear equations, Fourier transforms, and back-projection algorithms to the multiple lower resolution images in processing the multiple lower resolution images to produce a higher resolution image.

19. The device of claim 12, wherein the target is a barcode;

wherein the processor is configured to recognize barcode symbologies when determining the resolution requirements; and

wherein the processor is configured to send the higher resolution image to a decoder.