I'm trying to resize and save the 3 images as defined in the Page_load event.
Within method ResizeAndSave I have 2 methods I'm trying: FastResize and SlowResize.
When I uncomment the FastResize codeline: IMAGE 1 and 2 are saved and resized correctly. IMAGE 3 however, is saved in dimensions 625x441px and so does not respect the 200x200 box I want it to resize to.
When I instead use the SlowResize codeline: IMAGE 1 and 2 are again saved and resized correctly. IMAGE 3 however, is not saved at all.
No errors are thrown in my code. I will import images from a variety of sources so it's critical my code works on a wide range of image formats. And apparently there's something special about IMAGE 3 and I don't know what it is or how to handle it.
Here's my full code, you should be able to just copy/paste it and test it for yourself:
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.IO
Imports System.Xml
Imports System.Data.SqlClient
Imports System.Net
Imports System.Windows.Media.Imaging
Imports System.Windows.Media
Partial Class importfeeds
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'IMAGE 1
ResizeAndSave(200, 200, "https://upload.wikimedia.org/wikipedia/commons/8/82/Dell_Logo.png")
'IMAGE 2
ResizeAndSave(200, 200, "https://upload.wikimedia.org/wikipedia/commons/d/d8/Square-1_solved.jpg")
'IMAGE 3
ResizeAndSave(200, 200, "http://cdn2.emobassets.eu/media/catalog/product/1/1/1116220.jpg")
End Sub
Private Sub ResizeAndSave(ByVal maxWidth As Integer, ByVal maxHeight As Integer, ByVal imageURL As String)
Dim imgRequest As WebRequest = WebRequest.Create(imageURL)
Dim imgResponse As WebResponse = imgRequest.GetResponse()
Dim streamPhoto As Stream = imgResponse.GetResponseStream()
Dim memStream As New MemoryStream
streamPhoto.CopyTo(memStream)
memStream.Position = 0
Dim bfPhoto As BitmapFrame = ReadBitmapFrame(memStream)
Dim newWidth, newHeight As Integer
Dim scaleFactor As Double
If bfPhoto.Width > maxWidth Or bfPhoto.Height > maxHeight Then
If bfPhoto.Width > maxWidth Then
scaleFactor = maxWidth / bfPhoto.Width
newWidth = Math.Round(bfPhoto.Width * scaleFactor, 0)
newHeight = Math.Round(bfPhoto.Height * scaleFactor, 0)
End If
If newHeight > maxHeight Then
scaleFactor = maxHeight / newHeight
newWidth = Math.Round(newWidth * scaleFactor, 0)
newHeight = Math.Round(newHeight * scaleFactor, 0)
End If
End If
Dim bfResize As BitmapFrame = FastResize(bfPhoto, newWidth, newHeight)
'Dim bfResize As BitmapFrame = SlowResize(bfPhoto, newWidth, newHeight, BitmapScalingMode.Linear)
Dim baResize As Byte() = ToByteArray(bfResize)
Dim strThumbnail As String = Guid.NewGuid.ToString() + ".png"
Dim saveToPath As String = Server.MapPath(ConfigurationManager.AppSettings("products_photospath")) + "\49\" + strThumbnail
File.WriteAllBytes(saveToPath, baResize)
End Sub
Private Shared Function FastResize(bfPhoto As BitmapFrame, nWidth As Integer, nHeight As Integer) As BitmapFrame
Dim tbBitmap As New TransformedBitmap(bfPhoto, New ScaleTransform(nWidth / bfPhoto.PixelWidth, nHeight / bfPhoto.PixelHeight, 0, 0))
Return BitmapFrame.Create(tbBitmap)
End Function
'http://weblogs.asp.net/bleroy/resizing-images-from-the-server-using-wpf-wic-instead-of-gdi
Public Shared Function SlowResize(photo As BitmapFrame, width As Integer, height As Integer, scalingMode As BitmapScalingMode) As BitmapFrame
Dim group = New DrawingGroup()
RenderOptions.SetBitmapScalingMode(group, scalingMode)
group.Children.Add(New ImageDrawing(photo, New Windows.Rect(0, 0, width, height)))
Dim targetVisual = New DrawingVisual()
Dim targetContext = targetVisual.RenderOpen()
targetContext.DrawDrawing(group)
Dim target = New RenderTargetBitmap(width, height, 96, 96, PixelFormats.[Default])
targetContext.Close()
target.Render(targetVisual)
Dim targetFrame = BitmapFrame.Create(target)
Return targetFrame
End Function
Private Shared Function ToByteArray(bfResize As BitmapFrame) As Byte()
Using msStream As New MemoryStream()
Dim pbdDecoder As New PngBitmapEncoder()
pbdDecoder.Frames.Add(bfResize)
pbdDecoder.Save(msStream)
Return msStream.ToArray()
End Using
End Function
Private Shared Function ReadBitmapFrame(streamPhoto As Stream) As BitmapFrame
Dim bdDecoder As BitmapDecoder = BitmapDecoder.Create(streamPhoto, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.None)
Return bdDecoder.Frames(0)
End Function
End Class
UPDATE 1
@Hans Passant: Both your suggestions on filenaming and pixelWidth usage are spot on and helped me run this code successfully on the 3 images in the Page_load event.
I updated my original code.
However, when I run this code as part of my actual application, where I import ~100 images from a feed. The new code fails with an out of memory exception when it tries to process IMAGE 3. This happens for both FastResize and SlowResize methods. Is there something in my code or in the image in question that would cause this increase in memory usage, maybe a leak somewhere or an inefficient resizing method I use?
I have a lot of memory available on my machine, so would be very surprised if that were the problem, although I do see a big increase in the System and compressed memory (to 1.1GB) task in my Windows task manager. And still, this much memory usage would have me believe that there's something wrong in my code.
What can it be?
