Image stabilization method and image stabilization device
An image stabilization method and an image stabilization device are provided. In the method, each of images to be processed is detected by a feature point detection method to detect a plurality of feature points. The relationship of the same feature points in adjacent images to be processed is analyzed. According to the relationship of the feature points, a homography transform matrix of adjacent images to be processed is calculated. Based on the known feature points and the homography transform matrix, a stabilization matrix and a plurality of adjustment matrices corresponding to each image to be processed are calculated. Compensation is performed on each image to be processed by the adjustment matrices, so as to produce a plurality of corrected images. A first image of adjacent corrected images multiplied by the same stabilization matrix is transformed to a second image of the adjacent corrected images.
1. An image stabilization method for processing a plurality of images, comprising:
using a feature point detection method to detect each of the images to be processed, so as to detect a plurality of feature points in each of the images to be processed;
analyzing a relationship of same feature points in adjacent images to be processed;
calculating a homography transform matrix of the adjacent images to be processed according to the relationship of the feature points;
calculating a stabilization matrix and an adjustment matrix corresponding to each of the images to be processed according to the known feature points in each of the images to be processed and the homography transform matrices; and
compensating each of the images to be processed by the adjustment matrix, so as to produce a plurality of corrected images,
wherein a first image of adjacent corrected images multiplied by the same stabilization matrix is transformed to a second image of the adjacent corrected images.
2. The image stabilization method as claimed in claim 1 , wherein the step of calculating the stabilization matrix and the adjustment matrix corresponding to each of the images to be processed according to the known feature points in each of the images to be processed and the homography transform matrices comprises:
performing an optimization value operation on a function formed by taking the adjustment matrix and the stabilization matrix as variables according to the known feature points in each of the images to be processed and the homography transform matrices while taking minimization of the function as an objective, so as to calculate optimal solutions of the adjustment matrix and the stabilization matrix.
3. The image stabilization method as claimed in claim 2 , wherein the optimization value operation comprises performing the value operation by a non-linear optimization method.
4. The image stabilization method as claimed in claim 3 , wherein the non-linear optimization method comprises a sequential quadratic programming method, and solutions of the adjustment matrix and the stabilization matrix are calculated according to a recursion method.
5. The image stabilization method as claimed in claim 1 , wherein the step of analyzing the relationship of the same feature points in adjacent images to be processed comprises:
respectively detecting a motion vector of each of the feature points between a position of a first image and a position of a second image in the adjacent images to be processed.
6. The image stabilization method as claimed in claim 1 , further comprising using a feature point tracking method to analyze the relationship of the same feature points in the adjacent images to be processed, wherein the feature point tracking method comprises using an optical flow method to estimate a motion vector of each of the feature points.
7. The image stabilization method as claimed in claim 1 , wherein the feature point detection method comprises using a Harris feature point detection method to detect the feature points in each of the images to be processed.
8. An image stabilization device for processing a plurality of images, the image stabilization device comprising a memory storing a software modules and a processor executing the software module, wherein the software module comprising:
a feature point detection and analysis module, detecting each of the images to be processed for detecting a plurality of feature points in each of the images to be processed, and analyzing a relationship of same feature points in adjacent images to be processed;
a homography matrix calculation module, coupled to the feature point detection and analysis module, and calculating a homography transform matrix of the adjacent images to be processed according to the relationship of the feature points;
a trajectory smoothing module, coupled to the homography matrix calculation module, and calculating a stabilization matrix and an adjustment matrix corresponding to each of the images to be processed according to the known feature points in each of the images to be processed and the homography transform matrices; and
an image correction module, coupled to the trajectory smoothing module, and compensating each of the images to be processed by the adjustment matrix respectively, so as to produce a plurality of corrected images,
wherein a first image of adjacent corrected images multiplied by the same stabilization matrix is transformed to a second image of the adjacent corrected images.
9. The image stabilization device as claimed in claim 8 , wherein
the trajectory smoothing module performs an optimization value operation on a function formed by taking the adjustment matrix and the stabilization matrix as variables according to the known feature points in each of the images to be processed and the homography transform matrices while taking minimization of the function as an objective, so as to calculate optimal solutions of the adjustment matrix and the stabilization matrix.
10. The image stabilization device as claimed in claim 9 , wherein
the trajectory smoothing module performs the value operation by a non-linear optimization method.
11. The image stabilization device as claimed in claim 10 , wherein
the trajectory smoothing module uses a sequential quadratic programming method as the non-linear optimization method, and calculates solutions of the adjustment matrix and the stabilization matrix according to a recursion method.
12. The image stabilization device as claimed in claim 8 , wherein
the feature point detection and analysis module respectively detects a motion vector of each of the feature points between a position of a first image and a position of a second image in the adjacent images to be processed.
13. The image stabilization device as claimed in claim 12 , wherein
the feature point detection and analysis module uses a feature point tracking method to analyze the relationship of the same feature points in the adjacent images to be processed, wherein the feature point tracking method comprises using an optical flow method to estimate a motion vector of each of the feature points.
14. The image stabilization device as claimed in claim 8 , wherein
the feature point detection and analysis module uses a Harris feature point detection method to detect the feature points in each of the images to be processed.