public boolean equals(Object o) {
        if(!(o instanceof AsciiImage))
            return false;
        AsciiImage co = (AsciiImage)o;
        if(co.getHeight() != height || co.getWidth() != width)
            return false;
        for(int x=0; x<width; x++) {
            for(int y=0; y<height; y++) {
                if(getPixel(x,y) != co.getPixel(x,y))
                    return false;
            }
        }
        return true;
    }