Retaining highest resolution of a photo in upload?

[RickVidallon]

I have a .Net application written in C# where members may upload their
photos and have them displayed on our website. We are trying to
maintain the best quality using best settings in .Net for this.

A good commercial comparison is as follows;
I uploaded a photo to www.flickr.com. http://www.flickr.com/photos/visione...n/photostream/
The photo contains 73076 kbs. --- When I upload the 'same photo' to
our application it saves it at 13076 kbs. That's nice for speed but
not very good for quality.

Here is the settings we are using:
::::::::::::::: ::::::::::::::: ::::::::::::::: :::::::::::
System.Drawing.

Image image1 =
System.Drawing. Image.FromFile( Server.MapPath( imgfilepath +
actimgFilename) );
System.Drawing.

Image smallimage = new Bitmap (imgNewWidth, imgNewHeight,
image1.PixelFor mat);

Graphics oGraphic = Graphics.FromIm age(smallimage) ;
oGraphic.Compos itingQuality =

CompositingQual ity.HighQuality ;
oGraphic.Smooth ingMode =

SmoothingMode.H ighQuality;
oGraphic.Interp olationMode =

InterpolationMo de.HighQualityB icubic;
oGraphic.PixelO ffsetMode =

PixelOffsetMode .HighQuality;

Rectangle oRectange = new Rectangle (0, 0, imgNewWidth,
imgNewHeight);
oGraphic.DrawIm age(image1, oRectange);

smallimage.Save (Server.MapPath (imgfilepath + newFilename),
System.Drawing. Imaging.

ImageFormat.Jpe g);
::::::::::::::: ::::::::::::::: ::::::::::::::: :::::::::::
Thanks in advance,
Rick

[=?Utf-8?B?TWlsb3N6IFNrYWxlY2tpIFtNQ0FEXQ==?=]

Hi there Rick,

In order to control the output image quality you have to use
smallImage.Save (filename, ImageCodecInfo, EncoderParamete rs) overload,

using System.Drawing. Imaging;

public ImageCodecInfo GetEncoder(stri ng mimeType)
{
foreach (ImageCodecInfo encoder in ImageCodecInfo. GetImageEncoder s())
{
if (String.Compare (encoder.MimeTy pe, mimeType, true) == 0)
return encoder;
}

throw new Exception(Strin g.Format(
"cannot find encoder for MIME type {0}", mimeType);
}

and amend the method where you save transformed image:

long quality = 75L; // from 1 to 100
ImageCodecInfo encoder = GetEncoder("ima ge/jpeg");
EncoderParamete rs parameters = new EncoderParamete rs(1);
parameters.Para m[0] = new EncoderParamete r(Encoder.Quali ty, quality);

smallImage.Save (Server.MapPath (imgfilepath + newFilename), encoder,
parameters);

hope this helps

--
Milosz
"RickVidall on" wrote:

I have a .Net application written in C# where members may upload their
photos and have them displayed on our website. We are trying to
maintain the best quality using best settings in .Net for this.

A good commercial comparison is as follows;
I uploaded a photo to www.flickr.com. http://www.flickr.com/photos/visione...n/photostream/
The photo contains 73076 kbs. --- When I upload the 'same photo' to
our application it saves it at 13076 kbs. That's nice for speed but
not very good for quality.

Here is the settings we are using:
::::::::::::::: ::::::::::::::: ::::::::::::::: :::::::::::
System.Drawing.

Image image1 =
System.Drawing. Image.FromFile( Server.MapPath( imgfilepath +
actimgFilename) );
System.Drawing.

Image smallimage = new Bitmap (imgNewWidth, imgNewHeight,
image1.PixelFor mat);

Graphics oGraphic = Graphics.FromIm age(smallimage) ;
oGraphic.Compos itingQuality =

CompositingQual ity.HighQuality ;
oGraphic.Smooth ingMode =

SmoothingMode.H ighQuality;
oGraphic.Interp olationMode =

InterpolationMo de.HighQualityB icubic;
oGraphic.PixelO ffsetMode =

PixelOffsetMode .HighQuality;

Rectangle oRectange = new Rectangle (0, 0, imgNewWidth,
imgNewHeight);
oGraphic.DrawIm age(image1, oRectange);

smallimage.Save (Server.MapPath (imgfilepath + newFilename),
System.Drawing. Imaging.

ImageFormat.Jpe g);
::::::::::::::: ::::::::::::::: ::::::::::::::: :::::::::::
Thanks in advance,
Rick

[=?Utf-8?B?UGV0ZXIgQnJvbWJlcmcgW0MjIE1WUF0=?=]

Actually, depending on the image type, the most reliable way to "preserve
everything" is to save the entire byte stream using a FileStream and write it
to a file. In the case of Tiff images, for example, using one of the
Image.Save overloads will still lose information, due to a "not 100%
complete" implementation by Microsoft.
Peter

--
Site: http://www.eggheadcafe.com
UnBlog: http://petesbloggerama.blogspot.com
Short urls & more: http://ittyurl.net


"RickVidall on" wrote:

I have a .Net application written in C# where members may upload their
photos and have them displayed on our website. We are trying to
maintain the best quality using best settings in .Net for this.

A good commercial comparison is as follows;
I uploaded a photo to www.flickr.com. http://www.flickr.com/photos/visione...n/photostream/
The photo contains 73076 kbs. --- When I upload the 'same photo' to
our application it saves it at 13076 kbs. That's nice for speed but
not very good for quality.

Here is the settings we are using:
::::::::::::::: ::::::::::::::: ::::::::::::::: :::::::::::
System.Drawing.

Image image1 =
System.Drawing. Image.FromFile( Server.MapPath( imgfilepath +
actimgFilename) );
System.Drawing.

Image smallimage = new Bitmap (imgNewWidth, imgNewHeight,
image1.PixelFor mat);

Graphics oGraphic = Graphics.FromIm age(smallimage) ;
oGraphic.Compos itingQuality =

CompositingQual ity.HighQuality ;
oGraphic.Smooth ingMode =

SmoothingMode.H ighQuality;
oGraphic.Interp olationMode =

InterpolationMo de.HighQualityB icubic;
oGraphic.PixelO ffsetMode =

PixelOffsetMode .HighQuality;

Rectangle oRectange = new Rectangle (0, 0, imgNewWidth,
imgNewHeight);
oGraphic.DrawIm age(image1, oRectange);

smallimage.Save (Server.MapPath (imgfilepath + newFilename),
System.Drawing. Imaging.

ImageFormat.Jpe g);
::::::::::::::: ::::::::::::::: ::::::::::::::: :::::::::::
Thanks in advance,
Rick