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Optical Barcode Readers and Writers Understand the Problem This assignment combines 2D arrays, interfaces (including Cloneable), and a very active industrial application, optical scanning and pattern recognition. This will add some elegant code to your resume. Let's look at a Datamatrix. What do you notice about it? The more recognizable feature, perhaps, is the solid black on the left and bottom. This is called the Closed Limitation Line. Look a little more closely and you'll notice that the right and top consist of an alternating black and white pattern, so that the odd numbered pixels on the far right (and top) are black, while the even numbered pixels are white. This is called the Open Borderline. The Closed Limitation Line and Open Borderline help the algorithms because they:  Help situate the code in a standard position.  Determine the minimum size of each pixel.  Determine the height and width of the Datamatrix (which as you can see from the examples can vary). As you can see, I am using *s to indicate black pixels, and blanks to indicate white ones. Also, the bottom and left edge are "solid" black (you have to use your imagination a little) and the top and right are alternating black-white pixels. In order to read this message we need to start at the far left and look at each column. We throw away the left column which is part of the Closed Limitation Line and also throw away the bottom and top. The first column is, then: This tells us exactly how do read the code: It is 4 + 16 + 64 = 84 = 'T' (capital T). We then move to the next column, and decode that one the same way. This is pretty much punched paper tape from the 1970s (which was a great start on this concept). In summary, we are going to use the solid Closed Limitation Line and the Open Borderline simply to identify the size and extent of the code. After that, we'll look at (or print if we are creating the label) each column from left-to-right, converting the ASCII codes into a sequence of 8 characters, or visa-versa. It turns out, the structure of the classes, objects and algorithms we'll need to write will be adequate as a framework for the more complex and real Datamatrix, even though we will only program a faint suggestion of the real deal. There are three components (other than main()) to this assignment.  interface BarcodeIO. An Interface (which you define) called BarcodeIO that defines the I/O and basic methods of any barcode class which might implement it.  class BarcodeImage implements Cloneable. An object of this BarcodeImage class will be one of the main member-objects of the class that comes next. BarcodeImage will describe the 2D dot-matrix pattern, or "image". It will contain some methods for storing, modifying and retrieving the data in a 2D image. The interpretation of the data is not part of this class. Its job is only to manage the optical data. It will implement Cloneable interface because it contains deep data.  class DataMatrix implements BarcodeIO. The class that will contain both a BarcodeImagemember object and a text String member that represents the message encoded in the embedded image. This class has all the fun. This is not a true Datamatrix because, for one thing, there is no Reed-Solomon error correction.  ** Lastly, draw the UML diagram that represents the classes  Define an interface, BarcodeIO, that contains these method signatures. Any class that implements BarcodeIO is expected to store some version of an image and some version of the text associated with that image.  public boolean scan(BarcodeImage bc);  public boolean readText(String text);  public boolean generateImageFromText();  public boolean translateImageToText();  public void displayTextToConsole();  public void displayImageToConsole(); Now, as I said, this is an interface. So you should be able to do this part of the assignment in less than 60 seconds. Here are the descriptions of what these will do when implemented in the DataMatrix class, however, descriptions in an interface don't pack any punch in practice.  public boolean scan( BarcodeImage bc ) - accepts some image, represented as a BarcodeImage object to be described below, and stores a copy of this image. Depending on the sophistication of the implementing class, the internally stored image might be an exact clone of the parameter, or a refined, cleaned and processed image. Technically, there is no requirement that an implementing class use a BarcodeImageobject internally, although we will do so. For the basic DataMatrix option, it will be an exact clone. Also, no translation is done here - i.e., any text string that might be part of an implementing class is not touched, updated or defined during the scan.  public boolean readText( String text ) - accepts a text string to be eventually encoded in an image. No translation is done here - i.e., any BarcodeImage that might be part of an implementing class is not touched, updated or defined during the reading of the text.  public boolean generateImageFromText() - Not technically an I/O operation, this method looks at the internal text stored in the implementing class and produces a companion BarcodeImage, internally (or an image in whatever format the implementing class uses). After this is called, we expect the implementing object to contain a fully-defined image and text that are in agreement with each other.  public boolean translateImageToText() - Not technically an I/O operation, this method looks at the internal image stored in the implementing class, and produces a companion text string, internally. After this is called, we expect the implementing object to contain a fully defined image and text that are in agreement with each other.  public void displayTextToConsole() - prints out the text string to the console.  void displayImageToConsole() - prints out the image to the console. In our implementation, we will do this in the form of a dot-matrix of blanks and asterisks, e.g., Phase 1: BarcodeIO This class will realize all the essential data and methods associated with a 2D pattern, thought of conceptually as an image of a square or rectangular bar code. Here are the essential ingredients. This class has very little "smarts" in it, except for the parameterized constructor. It mostly just stores and retrieves 2D data. Remember: BarcodeImage implements Cloneable. DATA  public static final int MAX_HEIGHT = 30; public static final int MAX_WIDTH = 65; The exact internal dimensions of 2D data.  private boolean[][] image_data This is where to store your image. If the incoming data is smaller than the max, instantiate memory anyway, but leave it blank (white). This data will be false for elements that are white, and true for elements that are black. METHODS  Constructors. Two minimum, but you could have others: o Default Constructor - instantiates a 2D array (MAX_HEIGHT x MAX_WIDTH) and stuffs it all with blanks (false). o BarcodeImage(String[] str_data) -takes a 1D array of Strings and converts it to the internal 2D array of booleans. o HINT - This constructor is a little tricky because the incoming image is not the necessarily same size as the internal matrix. So, you have to pack it into the lower-left corner of the double array, causing a bit of stress if you don't like 2D counting. This is good 2D array exercise. The DataMatrix class will make sure that there is no extra space below or left of the image so this constructor can put it into the lower-left corner of the array.  Accessor and mutator for each bit in the image: boolean getPixel(int row, int col) and boolean setPixel(int row, int col, boolean value); For the getPixel(), you can use the return value for both the actual data and also the error condition -- so that we don't "create a scene" if there is an error; we just return false. For setPixel(), it will act like our usual mutators, returning true if the row and col are in range, and false if not.  Optional - A private utility method is highly recommended, but not required: checkSize(String[] data) It does the job of checking the incoming data for every conceivable size or null error. Smaller is okay. Bigger or null is not.  Optional - A displayToConsole() method that is useful for debugging this class, but not very useful for the assignment at large.  A clone() method that overrides the method of that name in Cloneable interface. Phase 2: BarcodeImage This class is a pseudo Datamatrix data structure, not a true Datamatrix, because it does not contain any error correction or encoding. However, it does have the 2D array format and a left and bottom BLACK "spine" as well as an alternating right and top BLACK-WHITE pattern as seen in the image. Remember: DataMatrix implements BarcodeIO. DATA  public static final char BLACK_CHAR = '*';  public static final char WHITE_CHAR = ' ';  private BarcodeImage image - a single internal copy of any image scanned-in OR passedinto the constructor OR created by BarcodeIO's generateImageFromText().  private String text - a single internal copy of any text read-in OR passed-into the constructor OR created by BarcodeIO's translateImageToText().  private int actualWidth and actualHeight - two ints that are typically less than BarcodeImage.MAX_WIDTH and BarcodeImage.MAX_HEIGHT which represent the actual portion of the BarcodeImage that has the real signal. This is dependent on the data in the image, and can change as the image changes through mutators. It can be computed from the "spine" of the image. METHODS  Constructors. Three minimum, but you could have more: o Default Constructor - constructs an empty, but non-null, image and text value. The initial image should be all white, however, actualWidthand actualHeight should start at 0, so it won't really matter what's in this default image, in practice. The text can be set to blank, "", or something like "undefined". o DataMatrix(BarcodeImage image) - sets the image but leaves the text at its default value. Call scan() and avoid duplication of code here. o DataMatrix(String text) - sets the text but leaves the image at its default value. Call readText() and avoid duplication of code here.  readText(String text) - a mutator for text. Like the constructor; in fact it is called by the constructor.  scan(BarcodeImage image) - a mutator for image. Like the constructor; in fact it is called by the constructor. Besides calling the clone()method of the BarcodeImage class, this method will do a couple of things including calling cleanImage() and then set the actualWidth and actualHeight. Because scan() calls clone(), it should deal with the CloneNotSupportedException by embeddingthe clone() call within a try/catch block. Don't attempt to hand-off the exception using a "throws" clause in the function header since that will not be compatible with the underlying BarcodeIO interface. The catches(...) clause can have an empty body that does nothing.  Accessors for actualWidth and actualHeight but no mutators! (why?) Phase 3: DataMatrix  private int computeSignalWidth() and private int computeSignalHeight() - Assuming that the image is correctly situated in the lower-left corner of the larger boolean array, these methods use the "spine" of the array (left and bottom BLACK) to determine the actual size.  Implementation of all BarcodeIO methods. Private method:  private void cleanImage() - This private method will make no assumption about the placement of the "signal" within a passed-in BarcodeImage. In other words, the incoming BarcodeImage may not be lower-left justified. The cleanImage() method would be called from within scan() and would move the signal to the lower-left of the larger 2D array. And, since scan() is called by the constructor, that implies that the image gets adjusted upon construction. This kind of standardization represents the many other image processing tasks that would be implemented in the scan() method. Error correction would be done at this point in a real class design. This is not hard to do, and it represents the kind of manipulation you would be expected to do in a real job, but it does require some helper methods (which are optional, meaning you can create your own if you don't like the sound of these): private void moveImageToLowerLeft(), private void shiftImageDown(int offset),private void shiftImageLeft(int offset). Other considerations for DataMatrix  displayImageToConsole() should display only the relevant portion of the image, clipping the excess blank/white from the top and right. Also, show a border as in:   Recommendation - The methods generateImageFromText() and translateImageToText(), are the tricky parts, and it will help if you have some methods like the following to break up the work: private char readCharFromCol(int col) and private boolean WriteCharToCol(int col, int code). While you don't have to use these exact methods, you must not turn in huge methods generateImageFromText() and translateImageToText() that are not broken down to smaller ones.  Optional - public void displayRawImage() can be implemented to show the full image data including the blank top and right. It is a useful debugging tool.  Optional - private void clearImage() - a nice utility that sets the image to white = false. You may need to digest what you are doing and why you are doing it at each juncture. If you just focus on each individual method, writing and testing as you go, you will be fine. Phase 4: Draw the UML diagram Use the tool, Gliffy, to build a UML diagram. Create an account and then export your diagram to PDF

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* BarcodeImage Class
public class BarcodeImage implements Cloneable {

// Fields
public static final int MAX_HEIGHT = 30;
public static final int MAX_WIDTH = 65;
private boolean[][] image_data;

// Constructor (no argument)
public BarcodeImage() {
image_data = new boolean[MAX_HEIGHT][MAX_WIDTH];

// Constructor (String array argument)
public BarcodeImage(String[] str_data) {
image_data = new boolean[MAX_HEIGHT][MAX_WIDTH];
for (int row = 0; row < MAX_HEIGHT; row++) {
for (int col = 0; col < MAX_WIDTH; col++) {
if (row < str_data.length && col < str_data[row].length() &&
str_data[row].charAt(col) == DataMatrix.BLACK_CHAR) {
image_data[row][col] = true;

// Method to get Pixel in BarcodeImage
public boolean getPixel(int row, int col) {
if (row >= 0 && row < MAX_HEIGHT && col >= 0 && col < MAX_WIDTH) {
return image_data[row][col];
} else {

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