Load Large Image (30Meg)

[Pino]

Ok I need to load large images up to 30Meg (PNG) and manipulate them when I use the following code I get an Out Of Memory Exception.

Anyone have any sample code for loading a large file via stream maybe?

//Now load the image back in and grab the size. 
                Image FullSizeImage = Image.FromFile(path + "\\high\\" + curPub.Image); //Error Here

                int width = FullSizeImage.Width;
                int height = FullSizeImage.Height;

                //Generate the thumb first.
                float ratio = width / 75;

                int thumbWidth = 75;
                int thumbHeight = Convert.ToInt32(height / ratio);

                Image ThumbnailImage = FullSizeImage.GetThumbnailImage(thumbWidth, thumbHeight, null, IntPtr.Zero);
                ThumbnailImage.Save(path + "\\images\\thumbnail\\" + curPub.Image, System.Drawing.Imaging.ImageFormat.Png);

[brin351]

You should not get "out of memory" for a 30meg file, If you just created/uploaded the file maybe it is not released and a file sharing issue is happening. I'm guessing because more details are needed.......

[gep13]

Hey,

I don't know if this will be much help or not, but these are the methods that I use for resizing images on the fly, I can't vouch for it working on a image of that size though, I have never tried it:

        private static byte[] ResizeImageFile(byte[] imageFile, int targetSize)
        {
            using (Image oldImage = Image.FromStream(new MemoryStream(imageFile)))
            {
                Size newSize = CalculateDimensions(oldImage.Size, targetSize);
                using (Bitmap NewImage = new Bitmap(newSize.Width, newSize.Height, PixelFormat.Format24bppRgb))
                {
                    using (Graphics canvas = Graphics.FromImage(NewImage))
                    {
                        canvas.SmoothingMode = SmoothingMode.AntiAlias;
                        canvas.InterpolationMode = InterpolationMode.HighQualityBicubic;
                        canvas.PixelOffsetMode = PixelOffsetMode.HighQuality;
                        canvas.DrawImage(oldImage, new Rectangle(new Point(0, 0), newSize));

                        MemoryStream m = new MemoryStream();
                        NewImage.Save(m, ImageFormat.Jpeg);
                        return m.GetBuffer();
                    }
                }
            }
        }

        public override Stream ResizeImageFile(Stream imageFile, PhotoSize targetSize)
        {
            if (targetSize == PhotoSize.Original)
            {
                //Return pic without resizing
                return imageFile;
            }
            else
            {
                Byte[] picBuff = StreamToBytes(imageFile);

                switch (targetSize)
                {
                    case PhotoSize.Large:
                        picBuff = ResizeImageFile(picBuff, 600);
                        break;
                    case PhotoSize.Medium:
                        picBuff = ResizeImageFile(picBuff, 198);
                        break;
                    case PhotoSize.Small:
                        picBuff = ResizeImageFile(picBuff, 100);
                        break;
                }

                return new MemoryStream(picBuff);
            }
        }

    public enum PhotoSize
    {
        Small = 1,		// 100px
        Medium = 2,		// 198px
        Large = 3,		// 600px
        Original = 4	// Original Size
    }

        private static Size CalculateDimensions(Size oldSize, int targetSize)
        {
            Size newSize = new Size();

            if (oldSize.Height > oldSize.Width)
            {
                newSize.Width = Convert.ToInt32(oldSize.Width * Convert.ToSingle(targetSize / Convert.ToSingle(oldSize.Height)));
                newSize.Height = targetSize;
            }
            else
            {
                newSize.Width = targetSize;
                newSize.Height = Convert.ToInt32(oldSize.Height * Convert.ToSingle(targetSize / Convert.ToSingle(oldSize.Width)));
            }

            return newSize;
        }

Hope that might help!!

Gary

[mendhak]

If this is happening right after an upload, chances are that the handle on the file hasn't been released, so you're attempting to read from a 0byte file.

If you need to manipulate it, do it straight from the byte array so that the file save and file manipulation happen separately.