Image Processor

Smita Rosemary and Ben Bishop – CS3500 Fall 2022, Northeastern University

Overview

This project represents an Image Processor that allows you to manipulate and enhance a given image.

The Image Processor allows a user to load in Image into the program, save it, and apply transformations such as:

• Visualizing the red, blue, green, alpha, luma, or intensity channels of each pixel in an image as a greyscale image
• Vertically or horizontally flipping an image
• Brightening or darkening an image

The user interacts with the Image Processor through the command line interface (CLI) and can load images into the processor, apply transformations, and save transformed images. Currently only .ppm files are supported.

How to Use

Upon launch, the user will be shown a welcome message, with the option to "quit" the program or view a "menu" of available commands. The user can enter the command quit at any time to exit the program.

All available commands are listed below:

• "quit" - quits the program
• "menu" - displays the menu of commands
• "load" - loads an image (identified by given name) into the processor
• "save" - saves an image to an output file
• "visualize-<component>" <filename> <new filename> - transforms an image to a new greyscale image using a chosen component
  • <component> can be "red", "green", "blue", "value", "intensity", or "luma"
• "brighten" <amount> <filename> <new filename> - transforms an image to a new image brightened by an amount
• "darken" <amount> <filename> <new filename> - transforms an image to a new image darkened by an amount
• "horizontal-flip" <filename> <new filename> - horizontally flips an image to a new image
• "vertical-flip" <filename> <new filename> - vertically flips an image to a new image

We have provided a test image located in the res folder named ExampleImage.ppm. We have also processed this image with all available commands to visualize transformations without running the program and saved them to the subfolder res/processed. ExampleImage.ppm was created by Smita Rosemary, and has been used with her permission.

Class Overview

Controller

• Interfaces
  • ImageProcessorController : Represents a controller for the image processor. As the user inputs commands, the controller validates the parameters and executes them. The controller also handles the exceptions thrown by the model and view, and displays them as messages to the user via the view.
    • Implementations:
      • ImageProcessorControllerImpl: Implements the ImageProcessorController interface supporting the above transformation commands as well as load, menu, and save.
  • ImageProcessorCmd : Represents a supported command that the image processor can handle. The command is executed by calling the execute method, and implemented subclasses of this interface will handle the execution of the command
    • Implementations:
      • LoadCmd : Implements the ImageProcessorCmd and represents the load command offered by the processor.
        • MenuCmd : Implements the ImageProcessorCmd and represents the menu command offered by the processor.
        • SaveCmd : Implements the ImageProcessorCmd and represents the save command offered by the processor.
        • BrightnessCmd : Implements the ImageProcessorCmd and represents the brighten and darken command offered by the processor.
        • HorizontalFlipCmd : Implements the ImageProcessorCmd and represents the horizontal-flip command offered by the processor.
        • VerticalFlipCmd : Implements the ImageProcessorCmd and represents the vertical-flip command offered by the processor.
        • VisualizeCmd : Implements the ImageProcessorCmd and represents the visualize-<componenet> command offered by the processor.
  • ImageFileHandler : Represents a model used to convert image files into Image objects.
    • Implementations:
      • ImagePPMHandler : Implements the ImageFileHandler interface for converting PPM image files into Image objects, and vice versa.

Model

• Interfaces

  • Image : Represents an image and it's pixels.

    • Implementations:
      • ImageImpl : Implements the Image interface, each image is represented by a 2D array of colors.

  • ImageTransformation : Represents a macro that can be applied to an Image to transform its pixels in some way.

    • Implementations:
      • Brightness : Implements the ImageTransformation interface and represents a macro that adjusts the brightness of an image, both up the scale and down.
        • HorizontalFlip : Implements the ImageTransformation interface and represents a macro that flips an image along the horizontal axis.
        • VerticalFlip: Implements the ImageTransformation interface and represents a macro that flips an image along the vertical axis.
        • Visualize : Implements the ImageTransformation interface and represents a macro that transforms the images to visualize the greyscale image by one of the following color components : visualize-red, visualize-blue, visualize-green , visualize-value, visualize-intensity, visualize-luma.

  • StoredImages : Represents a collection of Images that have been loaded into the program by the user, identified by the image's file name selected by the user.

    • Implementations:
      • StoredImagesImpl: Implements theStoredImages` interface. The stored images are represented by a Map<String, Image>, the string representing a fileName.

View

• Interfaces
  • ImageProcessorView : This interface represents the view of the Image Processor. It contains methods that the controller can call to render the view.
    • Implementations:
      • ImageProcessorViewImpl : Implements the ImageProcessorView interface and it's methods. Handles appending all the messages from the controller to the user.

Main Class

• ImageProcessorRunner : Contains the main method which runs the image processor in the terminal for the user.

Class Diagram

To more easily visualize these classes, we have provided a class diagram below: