Method and apparatus for generating image with shallow depth of field

• US 8,810,634 B2
• Filed: 07/29/2011
• Issued: 08/19/2014
• Est. Priority Date: 10/14/2010
• Status: Active Grant

• Current Assignee: Altek Corporation
• Original Assignee: Altek Corporation
• Inventors: Li, Yun-Chin
• Primary Examiner(s): Kelley, Christopher S
• Assistant Examiner(s): Tarko, Asmamaw G
• Application Number:
  US13/193,608
• Publication Number:
  US 20120092462A1
• Time in Patent Office: 1,117 Days
• Field of Search: 348/49, 348/E13.074
• US Class Current: 348/49
• CPC Class Codes: G02B 30/40 giving the observer of a single two-dimensional [2D] image a perception of depth
• CPC Class Codes: H04N 13/122 Improving the 3D impression of stereoscopic images by modifying image signal contents, e.g. by filtering or adding monoscopic depth cues H04N13/128 takes precedence
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

A method and an apparatus for generating an image with shallow depth of field, suitable for a three-dimensional imaging system having a left lens and a right lens, are provided. First, the left lens and the right lens are used to capture a left-eye image and a right-eye image. Next, a disparity between each of a plurality of corresponding pixels in the left and right-eye images is calculated. Then, the depth information of each pixel is estimated according to a focus of the left and right lens, a lens pitch between the left lens and the right lens, and the calculated disparity of each pixel. Finally, the pixels in the left-eye image and the right-eye image are blurred according to the focus of the left lens and the right lens and the estimated depth information of each pixel, so as to obtain the image with shallow depth of field.

Claims

1. A method for generating an image with shallow depth of field, suitable for a three-dimensional imaging system comprising a left lens and a right lens, the method comprises the following steps:

respectively utilizing the left lens and the right lens to capture a left-eye image and a right-eye image;

calculating a disparity between each of a plurality of corresponding pixels in the left-eye image and the right-eye image;

estimating a depth information of each pixel according to a focus that the left lens and the right lens adopts for capturing the left-eye image and the right-eye image, a lens pitch between the left lens and the right lens, and the calculated disparity of each pixel; and

blurring the pixels of the left-eye image or the right-eye image according to the focus of the left lens and the right lens and the estimated depth information of the pixels, so as to obtain an image with shallow depth of field,

wherein the step of blurring the pixels of the left-eye image or the right-eye image according to the focus of the left lens and the right lens and the estimated depth information of the pixels to obtain the image with shallow depth of field comprises;

utilizing the focus to obtain a focal plane;

calculating a distance between the pixel and the focal plane according to the depth information of each pixel; and

blurring the pixel according to the distance between each pixel and the focal plane, to obtain the image with shallow depth of field, wherein a level of the blurred pixel is proportional with the calculated distance between the pixel and the focal plane.

2. The method for generating an image with shallow depth of field as claimed in claim 1, wherein the step of calculating the disparity between each of the plurality of corresponding pixels in the left-eye image and the right-eye image comprises:

calculating a displacement between each pixel in the left-eye image and the right-eye image according to a position of each pixel in the left-eye image and the right-eye image, wherein the displacement is regarded as the disparity.

3. The method for generating an image with shallow depth of field as claimed in claim 1, wherein after the step of estimating the depth information of each pixel, the method further comprises:

comparing the depth information of the pixels, so as to identify at least one object in the left-eye image and the right-eye image, wherein each at least one object includes a plurality of adjacent pixels with similar depth information.

4. The method for generating an image with shallow depth of field as claimed in claim 3, wherein a difference value of the depth information of the adjacent pixels of each at least one object is less than a preset value.

5. The method for generating an image with shallow depth of field as claimed in claim 3, wherein the step of blurring the pixels of the left-eye image or the right-eye image according to the captured focus of the left lens and the right lens and the estimated depth information of the pixels, to obtain the image with shallow depth of field further comprises:

calculating a blur value of each at least one object; and

immensely blurring the object of the left-eye image or the right-eye image according to the captured focus of the left lens and the right lens and the blur value of the object, so as to obtain an image with shallow depth of field.

6. The method for generating an image with shallow depth of field as claimed in claim 5, wherein a level of the immensely blurred object is proportional with the calculated blur value of the object.

7. An apparatus for generating an image with shallow depth of field, comprising:

a left lens, to capture a left-eye image;

a right lens, to capture a right-eye image, wherein there is a lens pitch between the left lens and the right lens; and

a processing unit, coupled to the left lens and the right lens, to calculate a disparity between each of a plurality of corresponding pixels in the left-eye image and the right-eye image, to estimate a depth information of each pixel according to a focus that the left lens and the right lens adopts for capturing the left-eye image and the right-eye image, a lens pitch between the left lens and the right lens, and the disparity of each pixel, and to blur the pixels in the left-eye image or the right-eye image according to the focus of the left lens and the right lens and the depth information of each pixel, so as to obtain an image with shallow depth of field, wherein the processing unit utilizes the focus to obtain a focal plane, calculates a distance between the pixel and the focal plane according to the depth information of each pixel, and blurs the pixel according to the distance between each pixel and the focal plane, to obtain the image with shallow depth of field, wherein a level of the blurred pixel is proportional with the calculated distance between the pixel and the focal plane.

8. The apparatus for generating an image with shallow depth of field as claimed in claim 7, wherein the processing unit additionally compares the depth information of the pixels, to identify at least one object in the left-eye image and the right-eye image, and calculates a blur level of each at least one object, and accordingly immensely blurs the object in the left-eye image or the right-eye image, so as to obtain the image with shallow depth of field, wherein the identified each at least one object includes a plurality of adjacent pixels with similar depth information.