public static bool ResizeImage(Stream sourceStream, Stream targetStream, ImageFormat imageFormat, int maxWidth, int maxHeight, bool preserverAspectRatio, int quality)
{
System.Drawing.Image sourceImage;
try
{
sourceImage = System.Drawing.Image.FromStream(sourceStream);
sourceStream.Position = 0;
}
catch (OutOfMemoryException)
{
// This is not a valid image. Do nothing.
return false;
}
// If 0 is passed in any of the max sizes it means that that size must be ignored,
// so the original image size is used.
maxWidth = maxWidth == 0 ? sourceImage.Width : maxWidth;
maxHeight = maxHeight == 0 ? sourceImage.Height : maxHeight;
if (sourceImage.Width <= maxWidth && sourceImage.Height <= maxHeight)
{
sourceImage.Dispose();
sourceStream.CopyTo(targetStream);
return true;
}
Size oSize;
if (preserverAspectRatio)
{
// Gets the best size for aspect ratio resampling
oSize = GetAspectRatioSize(maxWidth, maxHeight, sourceImage.Width, sourceImage.Height);
}
else
oSize = new Size(maxWidth, maxHeight);
System.Drawing.Image oResampled = null;
Graphics oGraphics = null;
try
{
oResampled = new Bitmap(oSize.Width, oSize.Height, PixelFormat.Format24bppRgb);
// Creates a Graphics for the oResampled image
oGraphics = Graphics.FromImage(oResampled);
// The Rectangle that holds the Resampled image size
Rectangle oRectangle;
// High quality resizing
if (quality > 80)
{
oGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
// If HighQualityBicubic is used, bigger Rectangle is required to remove the white border
oRectangle = new Rectangle(-1, -1, oSize.Width + 1, oSize.Height + 1);
}
else
oRectangle = new Rectangle(0, 0, oSize.Width, oSize.Height);
// Place a white background (for transparent images).
oGraphics.FillRectangle(new SolidBrush(Color.White), oRectangle);
// Draws over the oResampled image the resampled Image
oGraphics.DrawImage(sourceImage, oRectangle);
sourceImage.Dispose();
if (imageFormat == ImageFormat.Jpeg)
{
ImageCodecInfo oCodec = GetJpgCodec();
if (oCodec != null)
{
EncoderParameters aCodecParams = new EncoderParameters(1);
aCodecParams.Param[0] = new EncoderParameter(Encoder.Quality, quality);
oResampled.Save(targetStream, oCodec, aCodecParams);
}
else
oResampled.Save(targetStream, imageFormat);
}
else if (imageFormat == ImageFormat.Gif)
{
try
{
// Use a proper palette
OctreeQuantizer quantizer = new OctreeQuantizer(255, 8);
using (Bitmap quantized = quantizer.Quantize(oResampled))
{
quantized.Save(targetStream, System.Drawing.Imaging.ImageFormat.Gif);
}
}
catch (System.Security.SecurityException)
{
// The calls to Marshal might fail in Medium trust, save the image using the default palette
oResampled.Save(targetStream, System.Drawing.Imaging.ImageFormat.Png);
}
}
else
{
oResampled.Save(targetStream, System.Drawing.Imaging.ImageFormat.Png);
}
}
finally
{
if (oGraphics != null)
oGraphics.Dispose();
if (oResampled != null)
oResampled.Dispose();
}
return true;
}
/// <summary>
/// Resizes the image.
/// </summary>
/// <param name="sourceFile">The source file.</param>
/// <param name="targetFile">The target file.</param>
/// <param name="maxWidth">Width of the max.</param>
/// <param name="maxHeight">Height of the max.</param>
/// <param name="preserverAspectRatio">if set to <c>true</c> [preserver aspect ratio].</param>
/// <param name="quality">The quality.</param>
/// <returns></returns>
public static bool ResizeImage(string sourceFile, string targetFile, int maxWidth, int maxHeight, bool preserverAspectRatio, int quality)
{
System.Drawing.Image sourceImage;
try
{
sourceImage = System.Drawing.Image.FromFile(sourceFile);
}
catch (OutOfMemoryException)
{
// This is not a valid image. Do nothing.
return(false);
}
// If 0 is passed in any of the max sizes it means that that size must be ignored,
// so the original image size is used.
maxWidth = maxWidth == 0 ? sourceImage.Width : maxWidth;
maxHeight = maxHeight == 0 ? sourceImage.Height : maxHeight;
if (sourceImage.Width <= maxWidth && sourceImage.Height <= maxHeight)
{
sourceImage.Dispose();
if (sourceFile != targetFile)
{
System.IO.File.Copy(sourceFile, targetFile);
}
return(true);
}
Size oSize;
if (preserverAspectRatio)
{
// Gets the best size for aspect ratio resampling
oSize = GetAspectRatioSize(maxWidth, maxHeight, sourceImage.Width, sourceImage.Height);
}
else
{
oSize = new Size(maxWidth, maxHeight);
}
System.Drawing.Image oResampled = null;
Graphics oGraphics = null;
try
{
oResampled = new Bitmap(oSize.Width, oSize.Height, PixelFormat.Format24bppRgb);
// Creates a Graphics for the oResampled image
oGraphics = Graphics.FromImage(oResampled);
// The Rectangle that holds the Resampled image size
Rectangle oRectangle;
// High quality resizing
if (quality > 80)
{
oGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
// If HighQualityBicubic is used, bigger Rectangle is required to remove the white border
oRectangle = new Rectangle(-1, -1, oSize.Width + 1, oSize.Height + 1);
}
else
{
oRectangle = new Rectangle(0, 0, oSize.Width, oSize.Height);
}
// Place a white background (for transparent images).
oGraphics.FillRectangle(new SolidBrush(Color.White), oRectangle);
// Draws over the oResampled image the resampled Image
oGraphics.DrawImage(sourceImage, oRectangle);
sourceImage.Dispose();
String extension = System.IO.Path.GetExtension(targetFile).ToLower();
if (extension == ".jpg" || extension == ".jpeg")
{
ImageCodecInfo oCodec = GetJpgCodec();
if (oCodec != null)
{
EncoderParameters aCodecParams = new EncoderParameters(1);
aCodecParams.Param[0] = new EncoderParameter(Encoder.Quality, quality);
oResampled.Save(targetFile, oCodec, aCodecParams);
}
else
{
oResampled.Save(targetFile);
}
}
else
{
switch (extension)
{
case ".gif":
try
{
// Use a proper palette
OctreeQuantizer quantizer = new OctreeQuantizer(255, 8);
using (Bitmap quantized = quantizer.Quantize(oResampled))
{
quantized.Save(targetFile, System.Drawing.Imaging.ImageFormat.Gif);
}
}
catch (System.Security.SecurityException)
{
// The calls to Marshal might fail in Medium trust, save the image using the default palette
oResampled.Save(targetFile, System.Drawing.Imaging.ImageFormat.Png);
}
break;
case ".png":
oResampled.Save(targetFile, System.Drawing.Imaging.ImageFormat.Png);
break;
case ".bmp":
oResampled.Save(targetFile, System.Drawing.Imaging.ImageFormat.Bmp);
break;
}
}
}
finally
{
if (oGraphics != null)
{
oGraphics.Dispose();
}
if (oResampled != null)
{
oResampled.Dispose();
}
}
return(true);
}
