Hello...I'm trying to speed up the thumbnail loads for a photo app. Is this the best way to draw a thumbnail? There's about 3 other functions involved but I'm just wondering about this particular one.
Code:private static void PrintImage(object o, PrintPageEventArgs e) { var img = new Bitmap(printImagePath); var p = new Point(10, 10); e.Graphics.DrawImage(img, p); img.Dispose(); //dispose of the image!!!! }
Thanks for any help.
That's not really showing a thumbnail...that's just showing the image at a particular location. Shouldn't you have some scaling in there?
If you understand what you're doing, you're not learning anything.
Here is the method I use ( to create a thumbnail from a source image's bytes ):
Code:byte[] GetFileThumbnail(byte[] srcImage, System.Drawing.Imaging.ImageFormat imageFormat) { System.IO.MemoryStream ms = new MemoryStream(srcImage); System.Drawing.Image image = System.Drawing.Image.FromStream(ms); System.Drawing.Image thumbnailImage = image.GetThumbnailImage(64, 64, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero); using (MemoryStream ms2 = new MemoryStream()) { thumbnailImage.Save(ms2,imageFormat); thumbnailImage.Dispose(); image.Dispose(); return ms2.ToArray(); } } public bool ThumbnailCallback() { return true; }
Basically you create a thumbnail for each image file using the above method, then draw the thumbnail image using the same method you would draw any image.
Last edited by Serapth; 11-23-2011 at 03:35 PM. Reason: Add thumbnailCallback()
Hmmm not sure...lemme check the functions calling it...
Here's the scaling:
Code:{ Image tempImage = Image.FromFile(imageData.Path); //imageData.size = tempImage.Size; //_albumData.setData(imageData, id); imageData.Size.Height = tempImage.Height; imageData.Size.Width = tempImage.Width; newPanel.BackgroundImage = Utilities.ScalImage(tempImage, new Size(_frameSize.Width*thumbNailQuality, _frameSize.Height*thumbNailQuality)); //imageData.size = newPanel.BackgroundImage.Size; tempImage.Dispose(); }
The better way is to not use the C# way. It's awfully slow.
ImageFast: A stand-alone library for quickly loading GDI+ images without validation. - Justin Rogers
After loading it you can then use this link:
[C#] Fast Acces To Bitmap Pixels? - C# | Dream.In.Code
I've used this class wonderfully, including heavy editing and it just blows the C# image handling out of the water.
He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
The fool wonders, the wise man asks. - Benjamin Disraeli
There are no foolish questions and no man becomes a fool until he has stopped asking questions. Charles Steinmetz
How do you call that thing?
Can't properly remember, not at my computer. But use those classes in your project. Then you can use inheritance to expand the individual functionality.
Excuse the type case!Code:unsafebitmap ub = new ub(imagefast.fromfile(filepath));
