Graphics.Drawimage does not work correctly

Question

Hi

I have the following code.

Bitmap memBmp;  

defaultBmp.Save("default.jpg" , System.Drawing.Imaging.ImageFormat.Jpeg );  

memBmp = new Bitmap(width, height);  // witdth > defaultBmp.Width and height > defaultBmp.Height  
Graphics g = Graphics.FromImage(memBmp);  

SolidBrush brush = new SolidBrush(Color.Black);  
rect = new Rectangle(0, 0, memBmp.Width, memBmp.Height);  
g.FillRectangle(brush, rect);  
brush.Dispose();  

g.DrawImage(defaultBmp, new Point(xoffset, yoffset);  

memBmp.Save("after.jpg", System.Drawing.Imaging.ImageFormat.Jpeg );  

default.jpg

after.jpg

after.jpg has thin line at right and under side.
Why ?

Answer 1

The solution to this problem was to specify the wrap mode as follows:

        // Create a default bitmap.
        Bitmap defaultBmp = new Bitmap(160,62);
        g = Graphics.FromImage(defaultBmp);
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
        System.Drawing.Imaging.ImageAttributes wrapMode = new System.Drawing.Imaging.ImageAttributes();
        wrapMode.SetWrapMode(System.Drawing.Drawing2D.WrapMode.Tile);
        g.DrawImage(orgBmp,
                    new Rectangle(0, 0, defaultBmp.Width, defaultBmp.Height),
                        0, 0, orgBmp.Width, orgBmp.Height,
                        GraphicsUnit.Pixel, wrapMode);

Answer 2

You must use the original size, like :

int xoffset = 0, yoffset = 0;
g.DrawImage(defaultBmp, xoffset, yoffset, defaultBmp.Width, defaultBmp.Height);

Answer 3

According to the attached code, the painted bitmap defaultBmp(160, 62) is drawn on memBmp(200, 200) at Point(0, 0) without scaled. I’m Sorry, Any questions?

DrawImage(Image, Point):Draws the specified Image, using its original physical size, at the specified location.

Answer 4

An easy way to understand this problem is to tile the defaultBmp into a memBmp.

Answer 5

I see the same issue.
I have a general purpose app that resizes a source bitmap to a PictureBox control that is scaled and depending on scale factor sometime the last row and sometime the last column (and some time both) are not rendered to destination bitmap. InterpolationMode does not have any effect. Debugger data indicate that all my data is correct.
Copying pixel data manually works as expected.
This is the call from C#:
graphics.DrawImage(sourceBitmap, dstRect, srcRect, GraphicsUnit.Pixel);

and this is relevant data from VS debugger:
sourceBitmap.Width 15 int
sourceBitmap.Height 8 int

• srcRect {X = 0 Y = 0 Width = 15 Height = 8} System.Drawing.Rectangle
• dstRect {X = 0 Y = 0 Width = 480 Height = 256} System.Drawing.Rectangle
• currentView.ClientSize {Width = 480 Height = 256} System.Drawing.Size
  scale 32 float