Convert the image in a PictureBox into a bitmap

Question

I have used the following code to convert the image in a PictureBox into a Bitmap:

bmp = (Bitmap)pictureBox2.Image;

But I am getting the result as bmp = null. Can anyone tell me how I do this?

Solution 1

As per my understanding your have not assigned PictureBox's Image property, so that it is returning null on type cast.

PictureBox property automatically convert the Image format and if you see the tooltip on Image property, it will Show System.Drawing.Bitmap. Check your image property is correctly assigned.

Check this, it is working at my side.

private void button1_Click(object sender, EventArgs e)
{
    var bmp = (Bitmap)pictureBox1.Image;
}

private void TestForm12_Load(object sender, EventArgs e)
{
    pictureBox1.Image = Image.FromFile("c:\\url.gif");
}

/// Using BitMap Class

 Bitmap bmp = new Bitmap(pictureBox2.Image);

You can directly cast pictureBox2.Image to Bitmap as you are doing and also using the Bitmap class to convert to Bitmap class object.

Ref: Bitmap Constructor (Image).

You can find more options here with the Bitmap Class

Solution 2

Bitmap bitmap = new Bitmap(pictureBox2.Image)

http://msdn.microsoft.com/en-us/library/ts25csc8.aspx

Solution 3

I think you looking for this:

Bitmap bmp = new Bitmap(pictureBox2.Image)

Comments

[DjMalaikallan]

Hi Tilak , I just applied the code but it gives me an error as "Object Reference not set to an instance of an Object"

[Tilak]

have you checked pictureBox2.Image for null

[Nyerguds]

You should never use Image.FromFile(path). It is a simple wrapper around the New Bitmap(path) constructor which has no extra advantages at all but loses the more specific Bitmap type in the process. So just use the New Bitmap(path) constructor instead. Using new Bitmap(image) on the result is also not advised since it converts the image to 32bpp ARGB, which might not be desired if you're working specific image types you want to preserve on later saves or manipulations (like 24bpp RGB, or indexed images with palettes).