Week 3 Lab: Image Manipulator 3000

Objectives

Resources

Overview

In this assignment you will be developing an image manipulation program. The remaining laboratory assignments will build on this one, allowing you to improve your initial submission based on feedback from your instructor. The program itself will be capable of reading and writing multiple image formats including .jpg, .png, and a custom format: .msoe files. The program will also be able to apply simple transformations to the image like:

The transformations are applied to the image that appears on the screen (rather than the image originally loaded from the file) so that multiple transformations can be applied. For example, the user should be able to create a negative grayscale image by clicking both buttons.

Assignment

This assignment has been designed to provide numerous ways in which the program may be expanded. Students are encouraged to use their creativity to implement additional functionality beyond the requirements of the assignment; however, it is important to complete the required functionality before getting too carried away.

User Interface

Figure 1: User Interface1)

In short, you must implement the following functionality:

All of your classes should be placed in a package whose name matches your MSOE username.

Details

Handler Methods

Your user interface does not need to match Figure 1 but does need to facilitate all the functionality in an intuitive way. Additionally, you must at a minimum have the same five Buttons with the same text as Figure 1. If you would like to add keyboard shortcuts to the Buttons, see Mnemonics below. You must incorporate the following methods into your design:

You may use FXML but are not required to do so. If you choose not to use FXML, your JavaFX code should be broken up into several helper methods when constructing the GUI.

.msoe File Format

The custom .msoe file format is a text based file format for storing images. It is designed to be easy to load and save, but results in comparatively large file sizes. The contents of a very small image of a white-on-black + symbol is shown below:

MSOE
3 3
#000000 #FFFFFF #000000
#FFFFFF #FFFFFF #FFFFFF
#000000 #FFFFFF #000000

Your program should be able to load hamburger.msoe image in the images folder of the repository.

Loading and Saving Images

The program must support loading and saving .jpg, .png, and .msoe image file formats. The open button will open a FileChooser dialog that will allow the user to select the file to be loaded (showOpenDialog()). The program will use the extension to determine the format of the file and load the image. If the file extension is not supported or the file contents does not match the file extension, the program will display an error message. Pressing the reload button will reload the most recently loaded image.

The save button will open a FileChooser dialog box that will allow the user to select the destination folder and type in the filename and extension (showSaveDialog()). The program will then write the image to that file using the file format that matches the file extension. If an unsupported file extension is entered, the program will display an error message without attempting to save the image.

Both the open and save dialogs should default to an images folder in the project (at the same level as the src folder). You'll need to create this folder in your project.

You are responsible for writing your own ImageIO class for loading and saving images. The class must have the following public class methods:

If the extension on the file passed to either of these methods is .msoe then the appropriate private class method below is called to do the actual work.

Both read() and write() must throw an IllegalArgumentException if the path passed in has a file extension that specifies an unsupported image format.

You may use the ImageUtil class in the ImageUtil.jar to read and write files in the .jpg and .png formats. You must implement your own code to read and write .msoe files.

Grayscale

This transformation converts the image into a grayscale image. If the image is already grayscale, the transformation has no affect. In this transformation, the RGB components of each pixel are replaced with a single value. The replacement value can be calculated as: gray = 0.21R + 0.71G + 0.07B more info.

Grayscale

Grayscale Example

Negative

This transformation converts the image into a photo negative of the original image. In this transform, each RGB component is replaced with 1.0 - original value. Thus, an RGB value of (1.0, 1.0, 0.0) would become (0.0, 0.0, 1.0). more info.

Negative

Negative Example

Mnemonics

For each action in the program there will be a corresponding keyboard shortcut, allowing the user to navigate the program without a mouse. In JavaFX keyboard shortcuts are handled using Mnemonics. A Mnemonic is a device used to remember an idea or a collection of facts, such as PEMDAS for the order of arithmetic operations (Parenthesis, Exponent, Multiplication, Division, Addition, Subtraction). Mnemonics are not always acronyms (Every Good Boy Deserves Fudge for the lines on a treble clef, for example).

In JavaFX, a Mnemonic is made up of a KeyCombination and a Node that can generate an ActionEvent that will be activated when the KeyCombination is typed. The KeyCombination can be as simple as a single key or can include modifier keys, like control, alt, shift, etc. Adding the fantastic IntelliJ shortcut to automatically format your code, shift-ctrl-alt-L would look like this:

        KeyCombination keyCombination = new KeyCodeCombination(
            KeyCode.L,
            KeyCombination.CONTROL_DOWN,
            KeyCombination.ALT_DOWN,
            KeyCombination.SHIFT_DOWN
        );

Adding it to a Mnemonic so that keyCombination will trigger the format() method that will format all the code in the editor TextArea and add it to the current scene would be:

Mnemonic m = new Mnemonic(editor, keyCombination);
scene.addMnemonic(m);

Every Mnemonic you want to use needs to be added to the current Scene so JavaFX knows to listen for them.

If you are using FXML, Scene Builder has the option to add a Mnemonic to any node that generates an ActionEvent

Exception Handling

There are a number of situations that could cause your program to throw an exception. For example, if the file is not found, cannot be opened, or contains incorrectly formatted data, it is likely that an exception will be thrown. In these cases, the program should display a useful message.

Just For Fun

There are many additional enhancements that could build on the required functionality. You are encouraged to enhance this application using your creativity. A number of potential enhancements are included below; however, you should not feel limited to these suggestions.

Acknowledgment

This laboratory assignment was developed by Dr. Chris Taylor.

1) The label at the bottom center of the window is not required but is the first enhancement suggested in the Just for Fun section.
See your professor's instructions for details on submission guidelines and due dates.