Panoroma Creator

Environment:

• MATLAB R2017b

Execution:

• Main program
  • main.m

Resource Files:

• Original Photo Sets: imageset/
• Panoroma output directory: result/

Prerequisite

• Resize your photos(for faster processing speed) and use autostitch to find the focal length for each photo.
• Change the focal_length array

% main.m

% focal length for each photo stores here
focal_length = [
    ...
];

Details of Execution

Execute main.m will do the following processes.

1. Read Images

2. Warping

Warp each image to cylindrical coordinate.

3. Feature Extraction

• Using techniques:
  • Multi-Scale Harris corner detector
  • Adaptive Non-maximal suppression(one should set their desired num of interest points) desired_numOfInterestPt = 1000;
  • Sample 8x8 oriented patches as feature descriptor

4. Feature Matching

• Exhaustively calculate Euclidean distance between all features in two images.
• Find the smallest 2 pairs(by sorting first), say e1-nn and e2-nn are distance of the two pairs.
• Consider the smallest pair as feature match if the ratio e1-nn / e2-nn are lower than a threshold value.
• The threshold can be set at:

% main.m

nearestneighbor_threshold = 0.7;

• Reference to 5.1 section of paper [Brown, Szeliski, Winder, CVPR'2005]

5. Image Matching

• With RANSAC Approach

6. Combine Image and Blending

• Stitch images from leftmost to rightmost ones
• Use linear blending on overlapping sections

Result