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ImageComp.cc

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/*
    File:       ImageComp.cc

    Function:   Compare two image files

    Author:     Andrew Willmott

    Notes:      
*/

#include "cl/ArgParse.h"
#include <stdlib.h>
#include <unistd.h>

#include "gcl/Image.h"
#include "gcl/XGraphicsSystem.h"
#include "cl/Action.h"

Void ApplyToImageDiff(Action<ClrReal> &action, Image &image1, Image &image2,
            ImgChannel chn = chMono)
{
    Int     i, j;
    ClrReal temp;

    action.Start();
    
    for (i = 0; i < image1.Height(); i++)
        for (j = 0; j < image1.Width(); j++)
        {
            temp = image1.GetRealPixel(j, i, chn) - image2.GetRealPixel(j, i, chn);
            action.Process(temp);
        }   

    action.Stop();
}

ClrReal AbsImageDiff(Image &image1, Image &image2, Image &destImage)
{
    Int     i, j;
    Colour  c;
    ClrReal maxCmpt = 0.0;
    
    for (i = 0; i < image1.Height(); i++)
        for (j = 0; j < image1.Width(); j++)
        {
            Colour a = image1.GetPixel(j, i);
            Colour b = image2.GetPixel(j, i);

            c = a - b;
            c[0] = abs(c[0]);
            c[1] = abs(c[1]);
            c[2] = abs(c[2]);

            maxCmpt = Max(maxCmpt, Max(c[0], Max(c[1], c[2])));
            destImage.SetPixel(j, i, c);
        }

    return(maxCmpt);
}


// --- Main Program -----------------------------------------------------------


Int main(Int argc, Char **argv)
{
    XGraphicsSystem         *gs;       
    StatsFinder<ClrReal>    rstats, bstats, gstats;     
    RGBAImage               img1, img2, imgDiff;     
    XOffscreenPane          *offImg;       
    XBackedPane             *window;       
    FileName                fpath;       
    Char                    *file1, *file2;      
    Int                     useWin, noFork;
    ClrReal                 maxCmpt;
    
    // command-line options
    
    if (arg_parse(argc, argv, 
            "",                                         "usage: prog [options]",
            
            "%S",   &file1,                             "image file 1",
            "%S",   &file2,                             "image file 2",
            
            // Output options
            
            "-window", ARG_FLAG(&useWin),               "display image differences in window",
            "-noFork", ARG_FLAG(&noFork),               "Don't fork into background",
            0) < 0)
        exit(1);
    
    // Read two images
    
    fpath.SetPath(file1);
    if (img1.Load(fpath) != 0)
        exit(1);
    
    if (useWin)
    {
#ifndef DEBUG
        if (!noFork && fork())
            return(0);
#endif
        gs = new XGraphicsSystem;
        offImg = new XOffscreenPane;
        gs->CreateOffscreen(offImg, img1.Width(), img1.Height());
        window = new XBackedPane;
        gs->CreateWindow(window, "difference", img1.Width(), img1.Height());
        offImg->PutImage(img1);
        window->Attach(offImg);
        window->HandleExpose();
        gs->Spin();
    }
    
    fpath.SetPath(file2);
    if (img2.Load(fpath) != 0)
        exit(1);
    
    if (img2.Width() != img1.Width() || img2.Height() != img1.Height())
    {
        cerr << "Error: picture dimensions don't match." << endl;
        exit(1);
    }
    
    if (useWin)
    {
        offImg->PutImage(img2);
        window->HandleExpose();
        gs->Spin();
    }
        
    // Compare...
    
    ApplyToImageDiff(rstats, img1, img2, chRed);
    ApplyToImageDiff(gstats, img1, img2, chGreen);
    ApplyToImageDiff(bstats, img1, img2, chBlue);
    
    cout << "mean_R " << rstats.mean << endl;
    cout << "var_R " << rstats.variance << endl;
    cout << "dev_R " << sqrt(rstats.variance) << endl;
    cout << endl;
    cout << "mean_G " << gstats.mean << endl;
    cout << "var_G " << gstats.variance << endl;
    cout << "dev_G " << sqrt(gstats.variance) << endl;
    cout << endl;
    cout << "mean_B " << bstats.mean << endl;
    cout << "var_B " << bstats.variance << endl;
    cout << "dev_B " << sqrt(bstats.variance) << endl;
    cout << endl;
    cout << "mean_L " << dot(cRGBToLum, Colour(rstats.mean, gstats.mean, bstats.mean)) << endl;
    cout << "var_L " << dot(cRGBToLum, Colour(rstats.variance, gstats.variance, bstats.variance)) << endl;
    cout << "dev_L " << sqrt(dot(cRGBToLum, Colour(rstats.variance, gstats.variance, bstats.variance))) << endl;
    
    if (useWin)
    {
        imgDiff.SetSize(img1.Width(), img1.Height());
        maxCmpt = AbsImageDiff(img1, img2, imgDiff);    
        imgDiff.Scale(1.0 / maxCmpt);
        
        offImg->PutImage(imgDiff);
        window->HandleExpose();
        gs->Run();
    }
    
    return(0);
}

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