The best way to return an image to the response stream, using an ImageResult.
In the controller, load your image data to an Image object and then return a new ImageResult object as below,
Image img = LoadImage();
return new ImageResult { Image = img, ImageFormat = ImageFormat.Jpeg };
Here is the implementation of ImageResult,
public class ImageResult : ActionResult
{
public ImageResult() { }
public Image Image { get; set; }
public ImageFormat ImageFormat { get; set; }
public override void ExecuteResult(ControllerContext context)
{
// verify properties
if (Image == null)
{
throw new ArgumentNullException("Image");
}
if (ImageFormat == null)
{
throw new ArgumentNullException("ImageFormat");
}
// output
context.HttpContext.Response.Clear();
if (ImageFormat.Equals(ImageFormat.Bmp)) context.HttpContext.Response.ContentType = "image/bmp";
if (ImageFormat.Equals(ImageFormat.Gif)) context.HttpContext.Response.ContentType = "image/gif";
if (ImageFormat.Equals(ImageFormat.Icon)) context.HttpContext.Response.ContentType = "image/vnd.microsoft.icon";
if (ImageFormat.Equals(ImageFormat.Jpeg)) context.HttpContext.Response.ContentType = "image/jpeg";
if (ImageFormat.Equals(ImageFormat.Png)) context.HttpContext.Response.ContentType = "image/png";
if (ImageFormat.Equals(ImageFormat.Tiff)) context.HttpContext.Response.ContentType = "image/tiff";
if (ImageFormat.Equals(ImageFormat.Wmf)) context.HttpContext.Response.ContentType = "image/wmf";
using (MemoryStream ms = new MemoryStream())
{
Image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
ms.WriteTo(context.HttpContext.Response.OutputStream);
}
}
If you need to resize the image before proceeding, you can use this ImageResizer class to resize image on the fly. It includes resizing by BestFit, ConstrainProportions, FixedSize, Crop.
<pre> public static Image BestFit(Image image, int height, int width)
{
if (image.Height > image.Width)
{
return ConstrainProportions(image, height, Dimensions.Height);
}
else
{
return ConstrainProportions(image, width, Dimensions.Width);
}
}
public static byte[] ImageToByteArray(System.Drawing.Image imageIn)
{
MemoryStream ms = new MemoryStream();
imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
return ms.ToArray();
}
public static Image ByteArrayToImage(byte[] data)
{
ImageConverter ic = new ImageConverter();
Image img = (Image)ic.ConvertFrom(data);
return img;
}
public static Image ConstrainProportions(Image imgPhoto, int Size, Dimensions Dimension)
{
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
float nPercent = 0;
switch (Dimension)
{
case Dimensions.Width:
nPercent = ((float)Size / (float)sourceWidth);
break;
default:
nPercent = ((float)Size / (float)sourceHeight);
break;
}
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
}
public static Image FixedSize(Image imgPhoto, int Width, int Height)
{
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
//if we have to pad the height pad both the top and the bottom
//with the difference between the scaled height and the desired height
if (nPercentH < nPercentW)
{
nPercent = nPercentH;
destX = (int)((Width - (sourceWidth * nPercent)) / 2);
}
else
{
nPercent = nPercentW;
destY = (int)((Height - (sourceHeight * nPercent)) / 2);
}
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(Width, Height);
//bmPhoto.SetResolution(2, 2);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.Transparent);
grPhoto.InterpolationMode = InterpolationMode.Default;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
}
public static Image Crop(Image imgPhoto, int Width, int Height, int destX, int destY)
{
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(Width, Height, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
}
public static Image Crop(Image imgPhoto, int Width, int Height, AnchorPosition Anchor)
{
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
if (nPercentH < nPercentW)
{
//honrizontal
nPercent = nPercentW;
switch (Anchor)
{
case AnchorPosition.Top:
destY = 0;
break;
case AnchorPosition.Bottom:
destY = (int)(Height - (sourceHeight * nPercent));
break;
default:
destY = (int)((Height - (sourceHeight * nPercent)) / 2);
break;
}
}
else
{
//vertical
nPercent = nPercentH;
switch (Anchor)
{
case AnchorPosition.Left:
destX = 0;
break;
case AnchorPosition.Right:
destX = (int)(Width - (sourceWidth * nPercent));
break;
default:
destX = (int)((Width - (sourceWidth * nPercent)) / 2);
break;
}
}
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(Width, Height, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
}
public enum Dimensions
{
Width,
Height
}
public enum AnchorPosition
{
Top,
Center,
Bottom,
Left,
Right
}
}</pre>
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