Graphics.DrawImage OutofmemoryException

[kashi_rock]

Dear All,

I am trying to resize a large JPEG file (10550 * 8500 pixels and 31MB size on disk) but everytime I am getting Outofmemory exception error. Following is my code:

public Bitmap userResizeImage(string strPath, Image imImage)
        {

            int intHeight = 0;
            int intWidth = 0;
            Bitmap bmpBitmap = default(Bitmap);
            Graphics gGraphics = default(Graphics);
 
            try
            {
                if (imImage.Height < 7000 & imImage.Width < 7000)
                {
                    bmpBitmap = new Bitmap(strPath);
                }
                else
                {
                    if (imImage.Height > 7000 & imImage.Width > 7000)
                    {
                        intHeight = 7000;
                        decimal dblRatio = 7000 / Convert.ToDecimal(imImage.Height);
                        intWidth = Convert.ToInt16(dblRatio * imImage.Width);
                        if (intWidth > 7000)
                        {
                            dblRatio = 7000 / Convert.ToDecimal(intWidth);
                            intHeight = Convert.ToInt16(dblRatio * intHeight);
                            intWidth = 7000;
                        }
                    }
                    else if (imImage.Height > 7000 & imImage.Width < 7000)
                    {
                        decimal dblRatio = 7000 / Convert.ToDecimal(imImage.Height);
                        intHeight = 7000;
                        intWidth = Convert.ToInt16(dblRatio * imImage.Width);
                    }
                    else if (imImage.Height < 7000 & imImage.Width > 7000)
                    {
                        decimal dblRatio = 7000 / Convert.ToDecimal(imImage.Width);
                        intWidth = 7000;
                        intHeight = Convert.ToInt16(dblRatio * imImage.Height);
                    }

                    gGraphics = Graphics.FromHwnd(IntPtr.Zero);
                    bmpBitmap = new Bitmap(intWidth, intHeight, gGraphics);
                    gGraphics.Dispose();

                    bmpBitmap.SetResolution(imImage.HorizontalResolution, imImage.VerticalResolution);

                    using (gGraphics = Graphics.FromImage((Image)bmpBitmap))
                    {
                        gGraphics.Clear(Color.White);
                        gGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                        gGraphics.CompositingQuality = CompositingQuality.HighQuality;
                        gGraphics.SmoothingMode = SmoothingMode.HighQuality;
                        gGraphics.DrawImage(imImage, new Rectangle(0, 0, intWidth, intHeight), 0, 0, imImage.Width, imImage.Height, GraphicsUnit.Pixel);
                    }

                    return bmpBitmap;
                }

                return bmpBitmap;

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return null;
            }
            finally
            {
                gGraphics.Dispose();
            }
        }

Could anyone please help me out to resolve the issue?
Thanks in advance.

Kaushal Sharma

[Milk]

Although as a jpeg your image is 31MB, in memory it will be in bitmap form and assuming 24bit colour will require ~256MB to store (10550 * 8500 * 24) / (8 * 1024 * 1024). This could well be too much if your system is a little short on RAM. An image of that size cannot be displayed all at once, perhaps you could tell us a bit more about what you are doing.

[kashi_rock]

Milk,
Thanks for your reply, Its true that being the JPEG, size of images is too large. These are some inspection files which has been merged by the client using photoshop. I am working on an application which reads these images and show in a image control (with zoom and pan functionalities) but before assigning those images to the control, I am getting error on resizing.. I have spent almost a day in finding the solution but helpless.

Any ideas...

Regards,
Kaushal

[Milk]

Not sure but it seems GDI+ can throw an out of memory exception for a number of reasons, it might not be just the shear size.

Have you tested the code with a smaller image?
Have you tested the code with a different image of the same size (source might be corrupt in some way)?
Are you disposing of all created GDI objects when finished with?

[Lord_Rat]

Carve the image in to chunks, load the chunks one at a time in to a separate object and resize the chunks. Then, stitch them back together.

[kashi_rock]

Thanks all for your replies.
I have tested it with smaller images and works fine for example 12mb jpeg (6500 * 5500). I am disposing all gdi objects

[Milk]

Well unless anyone else has any bright ideas I would be thinking about implementing Lord_Rat's solution. Although it would seem slightly ironic if you end up effectively splitting the image up into what the client merged originally.