Image Manipulation Testing Environment

Since IR (my method, anyway) requires a few image manipulation functions, it only makes sense to build a small testing environment to aid in developing these functions.

In my CS 550 classes (Computer Graphics; it was a graduate-level class that was open to undergraduates), we did a lot of work with OpenGL and textures. Also, in CS 435, "Multimedia Information Systems," we did some work with OpenGL for displaying images. What I did for a testing environment was pull the code from a 435 project (I belive it was an implementation of image blur) and modified it a bit to display an image stored in an object. This object is an instance of a class Iris, which will be responsible for reading in the image and manipulating it to extract the necessary information. The image is accessible via a public function, and glDrawPixels() is used in the Display() function to draw the image onscreen.

The following is my main.cpp; it compiles with g++ on Ubuntu linux with the following command:

$ g++ -lGL -lGLU -lglut -lX11 main.cpp

I'm not 100% sure if all of these arguments are required for an OpenGL program, but this sequence has served me well in development. I also often add the -ggdb switch so I can run the program through the gdb debugger, which is a lifesaver when it comes to segfaults.

#include <stdlib.h>
#include <GL/glut.h>
#include <GL/glu.h>

void Display();
void Update();
void Mouse(int, int, int, int);
void MouseMove(int, int);
void Keyboard(unsigned char, int, int);
void Special(int, int, int);
void SpecialKey(int, int, int);
void Reshape(int, int);
void Context(int);

#include "iris.h"
Iris* iris;

// World Window Size
int ww_height=600, ww_width=800,
// (Physical) Window Size (aka Viewport)
    w_height=600, w_width=800;


void init() {
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);

    glutInitWindowSize(ww_width, ww_height);
    glutInitWindowPosition(0,0);
    glutCreateWindow("Iris Parse");

    glutDisplayFunc(Display);
    glutIdleFunc(Update);
    glutMouseFunc(Mouse);
    glutMotionFunc(MouseMove);
    glutKeyboardFunc(Keyboard);
    glutSpecialFunc(SpecialKey);
    glutReshapeFunc(Reshape);

    glClearColor(0.0, 0.0, 0.0, 0.0);

    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_BLEND);
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
    glPolygonMode(GL_FRONT, GL_FILL);
    glPolygonMode(GL_BACK, GL_LINE);

}

int main(int argc, char** argv) {
    glutInit(&argc, argv);
    init();

    if (argc>=2)
        iris = new Iris(argv[1]);
    else
        iris = new Iris("eye_color.ppm");

    iris->process();

    ww_height=w_height=iris->height();
    ww_width=w_width=iris->width();

    glutMainLoop();

    return 0;
}

void Update() {glutPostRedisplay();}

int x=-1, y=-1;
void Display() {
    glClear(GL_COLOR_BUFFER_BIT);

    glRasterPos2i(x, y);
    glDrawPixels(iris->width(), iris->height(), GL_RGB, GL_UNSIGNED_BYTE, iris->data());

    glFlush();
    glutSwapBuffers();
}

void Mouse(int button, int state, int x, int y) {}

void MouseMove(int x, int y) {y=w_height-y;}

void Keyboard(unsigned char key, int x, int y) {}

void SpecialKey(int key, int xx, int yy) {
    if (key == GLUT_KEY_LEFT)        x += 1;
    else if (key == GLUT_KEY_RIGHT)  x -= 1;
    else if (key == GLUT_KEY_UP)     y += 1;
    else if (key == GLUT_KEY_DOWN)   y -= 1;
}

void Reshape(int w, int h) {
    ww_height=w_height=h;
    ww_width=w_width=w;
}