IBMR Assignment 1 Stitching Photo Mosaics
Feb 06, 2016
IBMR Assignment 1Stitching Photo Mosaics
What is Photo Mosaic?• Stitching photos to construct a wild-view scene.• Part1: CORNER DETECTION• Part2: PERSPECTIVE MAPPING and
MOSAICING• Handout after Part2 Finished
CORNER DETECTION
Requirement• Read an image, detect its all corner by HARRIS
CORNER DETECTION• (bonus) Invariant or robust features on scale,
orientation, illumination
Support• A GDI+ Image Loader• You may use any other library(openCV, matlab,
etc) except existing corner detection function.
About GDI+• Get color from Pixel(X,Y) in gbmpPicL• Color c;• gbmpPicL->getPixel(X, Y, &c);• int red = c.GetR();
• Set color at Pixel(X,Y) in gbmpPicL• gbmpPicL->setPixel(X, Y, Color(0,255,0)); //draw green at
(X,Y)
About Harris Detection• Preprocessing: Gaussian Filter / Gray level• Consider the matrix for a small square around (x,y)• Compute x and y derivatives : and • Compute • Find λ1 and λ2 by evaluation of eigenvalues or SVD
or• Compute the response of the detector at each pixel: Positive: corner Negative: edge Small: flat
k~0.04 to 0.06 + and
Next Step• Show the response
cited from http://www.ikaros-project.org/articles/2004/monoculardepth1/
• Non-Maxima suppression
cited from http://ssip2003.info.uvt.ro/lectures/chetverikov/edge_detection.pdf
Result – Try your own photo!•