## CPSC 120 Postlab 4: Color Bars Due before class on Monday, September 28, 2009

### Overview

For artists that work digitally, the color accuracy of a display can have tremendous implications for their work. For example, if an artist's display desaturates green slightly, then an image with people would be printed with sickly green looking people. In order to remedy this, the color of the device must be calibrated to a range of known colors. The colors for calibration are often displayed using vertical bars of color. In this assignment you will write a program that can generate color bars by interpolating two different colors.

Your program should display a window with five vertical color bars of equal size. The left and right color bars should be random Colors. The bar in the middle should be a 50%-50% blend of the right and left color bars. The center right and center left color bars should be 75%-25% blend of the right and left color bars (switching which is 75% and which is 25% to create two different colors).

In order to accomplish this you will need to interpolate colors, which can be achieved by interpolating each of the RGB values that constitute a color. In order to linearly interpolate two numbers you can use the following equation:

```	xi = x1 * (p1 / 100) + x2 * (p2 / 100)
```
Where xi is a value that is p1 percent of x1 and p2 percent of x2. Note that p1 and p2 must sum to 100.

• First declare your variables. You will probably need variables for each of the colors that will be drawn. The Color objects for the left and right color bars can be initialized to random colors when the variables are declared. The value of the other three colors, however, must be calculated from the left and right colors. In order to calculate the remaining colors using the interpolation equation above you can read the RGB values using the get methods (getRed(), getGreen(), and getBlue()) of the Color class. Once you calculate new RGB values you can use the constructor of the Color class to create a new Color object.
• When you have variables representing all five colors you can draw five filled rectangles to the window, one of each color in the appropriate location.

### Other Requirements

As usual, use good programming techniques. You should use good variable names, constants where appropriate, whitespace, and correct indentation and alignment of statements. Be sure to put your name, the file name, and a description of the program in the header. The program should be broken up into logical sections and each section should be documented with a brief description of what it does.

### Submission

To submit your code cp a tgz file containing your java file to the directory:

```   /home/staff/bouchard/CPSC120B/post4
```