Spot the Difference Game

Overview

• Term project in Embedded Vision course (Undergraduate)
• Application of Image Processing with using OpenCV
• If you want more information about its source code, visit my Github

Idea

• For easy control, this program is based on mouse-click actions
• Contours detection is the main function in this program process

Description

• Have 3 levels of difficulty, Hard-Normal-Easy
• Time limit is depend on the level of difficulty
• Contours Detection
  • Use 3 OpenCV methods
    • cvAbsDiff()
    • cvFindContours()
    • cvDrawContours()
  • More information about these 3 methods, refer some documentation sites

cvAbsDiff()

• Format
  • cvAbsDiff(CvArr* src1, CvArr* src2, CvArr* dst)
• Function
  • Solve the absolute value from the difference between src1 and src2 (matrix form)
  • Put the solved absolute value in dst variable
  • For this program, this method solves the difference value between original image and manipulated image

cvFindContours()

• Format
  • cvFindContours(CvArr* image, CvMemStorage* storage, CvSeq** firstContour, int headerSize = sizeof(CvContour), int mode = CV_RETR_LIST, int method = CV_CHAIN_APPROX_SIMPLE, CvPoint offset = cvPoint(0,0))
• Function
  • Find the number of contours in binary image (Convert from input image)
  • Return variable (sequence), firstContour is the outermost contour
  • For this program, this method solves the contours from the result image of cvAbsDiff() method
• Parameters
  • image
    • Input image (original), must be 8-bit single channel image(Binary Image)
  • storage
    • Memory that searched contours are saved in
  • firstContour
    • The pointer of the outermost contour
  • headerSize
    • Size of Sequence Header
  • mode
    • CV_RETR_EXTERNAL
    • CV_RETR_LIST
    • CV_RETR_CCOMP
    • CV_RETR_TREE
  • method
    • CV_CHAIN_CODE
    • CV_CHAIN_APPROX_NONE
    • CV_CHAIN_APPROX_SIMPLE
    • CV_CHAIN_APPROX_TC89_L1, CV_CHAIN_APPROX_TC89_KCOS
    • CV_LINK_RUNS
  • offset

cvDrawContours()

• Format
  • cvDrawContours(CvArr* img, CvSeq* contour, CvScalar external_color, CvScalar hole_color, int max_level, int thickness = 1, int lineType = 8)
• Function
  • Draw the contours from CvSeq* contour
  • Differentiate exterior or hole before drawing
  • For this program, this method draws the contours from the result of cvFindContours() method
• Parameters
  • image
  • contour
    • Contours information from cvFindContours() method
  • external_color
  • hole_color
  • max_level
  • thickness
  • lineType

Result

• Game start & Setting levels difficulty

  

  Game Start

  

  Level difficulty

• Game play screen

  

  Game Play - Inital mode

  

  Game Play - Running mode

• Game clear & over

  

  Game Clear

  

  Game Over

Development Environment

• Visual Studio 2017 (C++ language)
• OpenCV

Reference

• Contours detection in OpenCV
• Documentation_cvAbsDiff()
• Documentation_cvFindContours()
• Documentation_cvDrawContours()