OpenCV 图像处理 哈哈镜效果

两个效果：放大和挤压，分别由MaxFrame和MinFrame函数实现， 可直接使用在摄像头中：

void MaxFrame(IplImage* frame)
{
    uchar* old_data = (uchar*)frame->imageData;
    uchar* new_data = new uchar[frame->widthStep * frame->height];
    
    int center_X = frame->width / 2;
    int center_Y = frame->height / 2;
    int radius = 400;
    int newX = 0;
    int newY = 0;

    int real_radius = (int)(radius / 2.0);
    for (int i = 0; i < frame->width; i++)
    {
        for (int j = 0; j < frame->height; j++)
        {
            int tX = i - center_X;
            int tY = j - center_Y;

            int distance = (int)(tX * tX + tY * tY);
            if (distance < radius * radius)
            {
                newX = (int)((float)(tX) / 2.0);
                newY = (int)((float)(tY) / 2.0);

                newX = (int) (newX * (sqrt((double)distance) / real_radius));
                newX = (int) (newX * (sqrt((double)distance) / real_radius));

                newX = newX + center_X;
                newY = newY + center_Y;

                new_data[frame->widthStep * j + i * 3] = old_data[frame->widthStep * newY + newX * 3];
                new_data[frame->widthStep * j + i * 3 + 1] =old_data[frame->widthStep * newY + newX * 3 + 1];
                new_data[frame->widthStep * j + i * 3 + 2] =old_data[frame->widthStep * newY + newX * 3 + 2];
            }
            else
            {
                new_data[frame->widthStep * j + i * 3] =  old_data[frame->widthStep * j + i * 3];
                new_data[frame->widthStep * j + i * 3 + 1] =  old_data[frame->widthStep * j + i * 3 + 1];
                new_data[frame->widthStep * j + i * 3 + 2] =  old_data[frame->widthStep * j + i * 3 + 2];
            }
        }
    }
    memcpy(old_data, new_data, sizeof(uchar) * frame->widthStep * frame->height);
    delete new_data;
}

void MinFrame(IplImage* frame)
{
    uchar* old_data = (uchar*)frame->imageData;
    uchar* new_data = new uchar[frame->widthStep * frame->height];

    int center_X = frame->width / 2;
    int center_Y = frame->height / 2;

    int radius = 0;
    double theta = 0;
    int newX = 0;
    int newY = 0;

    for (int i = 0; i < frame->width; i++)
    {
        for (int j = 0; j < frame->height; j++)
        {
            int tX = i - center_X;
            int tY = j - center_Y;

            theta = atan2((double)tY, (double)tX);
            radius = (int)sqrt((double)(tX * tX) + (double) (tY * tY));
            int newR = (int)(sqrt((double)radius) * 12);
            newX = center_X + (int)(newR * cos(theta));
            newY = center_Y + (int)(newR * sin(theta));

            if (!(newX > 0 && newX < frame->width))
            {
                newX = 0;
            }
            if (!(newY > 0 && newY < frame->height))
            {
                newY = 0;
            }

            new_data[frame->widthStep * j + i * 3] = old_data[frame->widthStep * newY + newX * 3];
            new_data[frame->widthStep * j + i * 3 + 1] =old_data[frame->widthStep * newY + newX * 3 + 1];
            new_data[frame->widthStep * j + i * 3 + 2] =old_data[frame->widthStep * newY + newX * 3 + 2];
        }
    }
    memcpy(old_data, new_data, sizeof(uchar) * frame->widthStep * frame->height);
    delete new_data;
}