Jeff's September 20 Class Notes
[Note: this webpage last modified Friday, 04-Feb-2011 19:44:51 EST]
Adinistrative...
Questions on homework or quiz?
Exam Friday (september 24) - sample exam and topics list today!
HW3 grades and total grade so far in BB.
Outline for HW4 problem 2.
Hint for HW4 problem 3.
Today - more practice with "if", two different ways to do BB.
Advice on steps to write a program: (1) Understand exactly what it is supposed to do, e.g., what would a picture look like after running the function on it. (2) Write down a way that you would do this - the basic idea, a few sentences (e.g., for red eye removal, change any pixel that is close to red to black). (3) Write down "pseudocode" - the basic outline of what your program will look like to achieve what you want to do. For example, with red eye removal it could be something like
(a) function definition line, take a picture as input.
(b) for each pixel in the picture do the following.
(c) if the pixel's red value is above 200, then change the pixel's color to be black.
Step (4) - take your pseudocode and write your function. Then of course, step (5) is to debug/test your function.Each step along the way you are getting more and more precise about how exactly you are going to solve the problem. If you take your time and think things out, you will get to the final solution much faster!
Go through this process for making black and white.
Class activity - you go through the process for "line detection".
For next time - chromaKey to take one picture and put into another. Also go over any questions about the sample exam.
And make sure to take the quiz, and type things into JES to try them out!