1. Image Processing
CS177

2. Announcements Project 5 due next week
Next week's recitation will be review for final exam
Extra columns on blackboard to show average in projects, labs and exams
Sample exam will be posted by Monday

3. Questions?

4. Color System
RGB : colors are made using combination of Red, Green and Blue
Widely used for electronic screens
CMYK : subtractive system in which colors are made using combination of Cyan, Magenta, Yellow and Key (Black)
Used in printers as the default paper color is white

5. Color Class
It uses RGB model – hence requires mixture of RGB to make final color
Color c = new Color(r, g, b);
r, g, b is quantity of colors Red, Green and Blue respectively
0<=r, g, b<=255
To get a particular component of a color, use getRed(), getGreen() or getBlue() method

6. Picture Class
Provides a way to deal with .jpg and .png files as a 2D array
It creates and saves only .jpg and .png files. Other formats are not acceptable
In get(int i, int j) and set(int i, int j, Color c), 'i' is column and 'j' is row number of the pixel

7. Merge two images of same size
Picture picture1 = new Picture( file1 ); Picture picture2 = new Picture( file2 );
int w = picture1.width();
int h = picture1.height();
Picture merged = new Picture(w,h);
for( int i = 0; i < w; i++ )
for( int j = 0; j < h; j++ ) {
int r = picture1.get(i, j).getRed() + opacity * picture2.get(i, j).getRed() / 100;
//same for green and blue
//what is wrong here?
merged.set(i,j,new Color(r, g, b)); }

9. Questions