Homework 3

Histogram Equalization

Description

    You can download lena.bmp here !
    You can also download OpenCV C++ template for Visual Studio 2015 here ! (Warning: If you use this template, please don't upload the whole project. Only the source codes should be submitted. e.g. main.cpp, funtion.h )

  • Write a program to generate images and histograms:
    • (a) original image and its histogram
    • (b) image with intensity divided by 3 and its histogram
    • (c) image after applying histogram equalization to (b) and its histogram

Announcement

  • You may use any programming language of your choice to implement the functions required in assignment #3, provided that you do not use any library calls except for basic image IO (e.g. OpenCV).

  • Grading policy
    • Please include the histogram of the final image. (As in the previous assignment).
    • You have to draw the histogram. The part where you calculate the histogram must be done hardcored, but you may output your statistics data to a file and use auxiliary program to assist you in drawing the bar graphs, i.e., Excel, gnuplot, sigmaplot, matplotlib, matlab.
  • Hint: You can use any programing language to implement homework. However don't just call libraries, if just call libraries you will get zero point.

FAQ

  • Q1: 有規定報告的頁數嗎?
      沒有，但建議不要超過4頁。報告內容簡短扼要即可。
  • Q2: 請問這次作業中二部分，把所有亮度除以三是指無條件捨去或四捨五入嗎??
      是的，無條件捨去或四捨五入都可以哦，每個pixel都是0-255的整數。
  • Q3: 如果讀檔時的格式是彩色，即rgb值相同的三個通道，那計算 histogram 是取其中一個通道的值加總就好還是三個通道一起計算？
      如果讀檔是格式是彩色，三個通道要個別計算唷，但最後附上的 histogram 可以取一個通道代表即可。
      建議直接用灰階讀檔即可。
  • Q4: 請問做出來的結果圖大概長怎樣？
      做出來的影像可以參照 HW3 封面，分別是b和c的結果圖。
  • Q5: 請問報告總共要多少張圖？
      三張圖和三張對應的直方圖共6張哦。
  • Q6: 請問可以用numpy一次處裡多個像素嗎? 像是用np.histogram, np.cumsum等函式？
      np.histogram 不能用，np.cumsum 可以。
      本次希望實作 histogram equalization，故 histogram 必須手刻。
      作圖的部分 可以call functions.
  • Q7: 請問之前作業實作過的函式，以後作業可以直接 call 現成函式嗎?
      可以哦，如果是之前作業手刻過的函式，之後用到可以任意 call function.

Have Fun

To err is human, to forgive, divine.
人非聖賢，孰能無過。

I:       Explain us deadlock and we'll hire you.
Me:   Hire me and I'll explain it to you.