IMG1 =新位图（imgName [0]）;
IMG2 =新位图（imgName [1]）;
 

Declared a bitmap which was

private Bitmap img1 = null;  
private Bitmap img2 = null;  

the image will be putted after selecting it from openFileDialog.
the selected images were placed in an array.

imgName = openFD.FileNames;

then button1 to display these image.

pictureBox1.Image = Image.FromFile(imgName[0]);  
pictureBox2.Image = Image.FromFile(imgName[1]);

i replaced the button1 code with this

img1 = Image.FromFile(imgName[0]);  
img2 = Image.FromFile(imgName[1]);

but an error occurs

Cannot implicitly convert type 'System.Drawing.Image' to 'System.Drawing.Bitmap'

I'd try to change the code to img1 = Bitmap.FromFile(imgName[0]);. but still has the same error.
Any suggestion how to correct or do this right?

img1 = new Bitmap(imgName[0]);
img2 = new Bitmap(imgName[1]);