Revised: Sat Apr 02 15:35:59 CDT 2016
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Table of contents
Preface
This module contains review questions and answers keyed to the module titled Image Java3004: Processing Algorithms, Image Inversion, and PictureExplorer Objects .
The questions and the answers are connected by hyperlinks to make it easy for you to navigate from the question to the answer and back again.
Questions
Question 1 .
True or False? A color value is inverted by subtracting the value from 256.
Question 2
True or False? The code in Listing 1 instantiates a new object of the PictureExplorer class.
| Listing 1 . Question 2. |
|---|
class Prob02Runner{
private Picture pic = new Picture("Prob02.jpg");public Prob02Runner(){//constructor
System.out.println("Dick Baldwin");}//end constructor
//----------------------------------------------------////Accessor method
public Picture getPicture(){return pic;} |
Question 3
True or False? The code in Listing 2 causes an image to be displayed in the format shown in Figure 1 .
| Listing 2 . Question 3. |
|---|
public void run(){
pic.addMessage("Dick Baldwin",10,20);pic.explore(); |
Figure 1 - Question 3.
Question 4
True or False? The availability of the explore method and the PictureExplorer class is very important in at least two respects:
- The explore method makes it easy to display copies of an image at various stages during the processing of the image. Once the PictureExplorer object is created and displayed, it won't be effected by subsequent changes to the image.
- The availability of a PictureExplorer object makes it easy to manually analyze the colors of the individual pixels in an imageencapsulated in that object.
Question 5
True or False? The algorithm shown in Listing 3 can be used to cause the image shown in Figure 2 to be transformed into the image shown in Figure 3 .
| Listing 3 . Question 5. |
|---|
Pixel[] pixelArray = pic.getPixels();for(Pixel pixel:pixelArray ){
pixel.setRed(255 - pixel.getRed());pixel.setGreen(255 - pixel.getGreen());
pixel.setBlue(0);}//end for loop |
Figure 3 - Question 5.
Question 6
True or False? An object of Ericson's Pixel class encapsulates an individual pixel from an image.
Question 7
True or False? The Pixel class defines a single method that can be called to invert the color of the pixel.
Question 8
True or False? The getPixels method belonging to a Picture object returns references to all of the Pixel objects encapsulated in the picture in a two-dimensional array where the dimensions ofthe array represent the horizontal and vertical coordinates of each pixel.
Question 9
True or False? The for loop shown in Listing 3 is of a type that is often referred to as a for-each loop.