Retaining highest res. of a photo in upload?
 

Anyone know of a work around in .Net to retain the highest possible resolution of a photo or image after compression or resizing?

Re: Retaining highest res. of a photo in upload?
 

Use this code:

Dim g As Graphics = Graphics.FromImage(YourBitmap)



g.SmoothingMode = SmoothingMode.HighQuality

g.InterpolationMode = InterpolationMode.HighQualityBicubic

g.PixelOffsetMode = PixelOffsetMode.HighQuality

And when saving use this:

Dim myParams As EncoderParameters = New EncoderParameters(1)

myParams.Param(0) = New EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 80)

YourBitmap.Save(YourPath, GetEncoderInfo(MimeType), myParams)

This is GetEncoderInfo function:

Public Function GetEncoderInfo(ByVal MimeType As String) As ImageCodecInfo

        Dim j As Integer

        Dim encoders As ImageCodecInfo()

        encoders = ImageCodecInfo.GetImageEncoders()

        j = 0

        Do While j < encoders.Length

            If encoders(j).MimeType = MimeType.Trim.Replace("pjpeg", "jpeg") Then

                Return encoders(j)

            End If

            j += 1

        Loop

        Return Nothing

End Function

Re: Retaining highest res. of a photo in upload?
 

Wow- that was quick. I am a designer researching this for my programmer -- who is too slammed to research this. We are trying to keep the highest quality for uploaded photos, much like www.flickr.com does for it's members.

When you upload a 4000px by 2000px 5 meg image to (Flickr) it will compress to 1/2 or 2.5 meg and display at the appropriate aspect ratio for their site.

Our .Net app is compressing the photo file sizes much smaller, where as uploading a test photo to Flickr will sace at 58760 Kb our app. will save the same photo at 17240 Kb.

I will share your feedback with him. Thank you for taking the time to reply. It is greatly appreciated.

Rick

Re: Retaining highest res. of a photo in upload?
 

ManicCW

Here is the string we are using (C#)

System.Drawing.
Image image1 = System.Drawing.Image.FromFile(Server.MapPath(imgfilepath + actimgFilename));
System.Drawing.
Image smallimage = new Bitmap (imgNewWidth, imgNewHeight, image1.PixelFormat);
Graphics oGraphic = Graphics.FromImage(smallimage);
oGraphic.CompositingQuality =
CompositingQuality.HighQuality;
oGraphic.SmoothingMode =
SmoothingMode.HighQuality;
oGraphic.InterpolationMode =
InterpolationMode.HighQualityBicubic;
oGraphic.PixelOffsetMode =
PixelOffsetMode.HighQuality;
Rectangle oRectange = new Rectangle (0, 0, imgNewWidth, imgNewHeight);
oGraphic.DrawImage(image1, oRectange);
smallimage.Save(Server.MapPath(imgfilepath + newFilename), System.Drawing.Imaging.
ImageFormat.Jpeg);

Re: Retaining highest res. of a photo in upload?
 

The only thing that you are missing is EncoderParameters. Use the above code to set quality of saved image.