Putting a smaller image within a larger image.

Question

I need to put a smaller image within a larger image. the smaller picture should be centered in the larger picture. I'm working with C# and OpenCV, does anyone know how to do this?

Krish not. I'm using OpenCV and C #. do you have any idea to help me? — Rafael Arthur, Oct 08 '12 at 19:21
There is a [helpful post](https://stackoverflow.com/questions/1224653/place-watermark-image-on-other-images-c-asp-net) on watermarking images that might help you out. I assume it is pretty close to the same process to what you are doing. Also, be sure to check [this article](http://www.codeproject.com/Articles/2927/Creating-a-Watermarked-Photograph-with-GDI-for-NET) at CodeProject for another example using GDI+. — Tim Goyer, Oct 08 '12 at 20:27

score 2 · Answer 1 · answered Apr 20 '15 at 08:23

2

this worked for me

LargeImage.ROI = SearchArea; // a rectangle
SmallImage.CopyTo(LargeImage);
LargeImage.ROI = Rectangle.Empty;

EmguCV of course

answered Apr 20 '15 at 08:23

oferb

127
1
5

Mark · Answer 2 · 2015-07-03T22:21:31.343

The above answer is great! Here's a complete method that adds the watermark to the lower right corner.

public static Image<Bgr,Byte> drawWaterMark(Image<Bgr, Byte> img, Image<Bgr, Byte> waterMark)
    {

        Rectangle rect;
        //rectangle should have the same ratio as the watermark
        if (img.Width / img.Height > waterMark.Width / waterMark.Height)
        {
            //resize based on width
            int width = img.Width / 10;
            int height = width * waterMark.Height / waterMark.Width;
            int left = img.Width - width;
            int top = img.Height - height;
            rect = new Rectangle(left, top, width, height);
        }
        else
        {
            //resize based on height
            int height = img.Height / 10;
            int width = height * waterMark.Width / waterMark.Height;
            int left = img.Width - width;
            int top = img.Height - height;
            rect = new Rectangle(left, top, width, height);
        }

        waterMark = waterMark.Resize(rect.Width, rect.Height, Emgu.CV.CvEnum.INTER.CV_INTER_AREA);
        img.ROI = rect;
        Image<Bgr, Byte> withWaterMark = img.Add(waterMark);
        withWaterMark.CopyTo(img);
        img.ROI = Rectangle.Empty;
        return img;
    }

Putting a smaller image within a larger image.

2 Answers2

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