public static Image Resize(System.Drawing.Image image, Resolution targetResolution, ResizeMode resizeMode)
{
int sourceWidth = image.Width;
int sourceHeight = image.Height;
int targetWidth = targetResolution.Width;
int targetHeight = targetResolution.Height;
// Supplied image is landscape, while the target resolution is portait OR
// supplied image is in portait, while the target resolution is in landscape.
// switch target resolution to match the image.
if ((sourceWidth > sourceHeight && targetWidth < targetHeight) || (sourceWidth < sourceHeight && targetWidth > targetHeight))
{
targetWidth = targetResolution.Height;
targetHeight = targetResolution.Width;
}
float ratio = 0;
float ratioWidth = ((float)targetWidth / (float)sourceWidth);
float ratioHeight = ((float)targetHeight / (float)sourceHeight);
if (ratioHeight < ratioWidth)
ratio = ratioHeight;
else
ratio = ratioWidth;
Bitmap newImage = null;
switch (resizeMode)
{
case ResizeMode.Normal:
default:
{
int destWidth = (int)(sourceWidth * ratio);
int destHeight = (int)(sourceHeight * ratio);
newImage = new Bitmap(destWidth, destHeight);
using (Graphics graphics = Graphics.FromImage(newImage))
{
graphics.Clear(Color.Transparent);
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.DrawImage(image, 0, 0, destWidth, destHeight);
}
break;
}
case ResizeMode.Crop:
{
if (ratioHeight > ratioWidth)
ratio = ratioHeight;
else
ratio = ratioWidth;
int destWidth = (int)(sourceWidth * ratio);
int destHeight = (int)(sourceHeight * ratio);
newImage = new Bitmap(targetWidth, targetHeight);
int startX = 0;
int startY = 0;
if (destWidth > targetWidth)
startX = 0 - ((destWidth - targetWidth) / 2);
if (destHeight > targetHeight)
startY = 0 - ((destHeight - targetHeight) / 2);
using (Graphics graphics = Graphics.FromImage((System.Drawing.Image)newImage))
{
graphics.Clear(Color.Transparent);
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.DrawImage(image, startX, startY, destWidth, destHeight);
}
break;
}
case ResizeMode.Stretch:
{
newImage = new Bitmap(targetWidth, targetHeight);
using (Graphics graphics = Graphics.FromImage((System.Drawing.Image)newImage))
{
graphics.Clear(Color.Transparent);
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.DrawImage(image, 0, 0, targetWidth, targetHeight);
}
break;
}
case ResizeMode.Fill:
{
newImage = new Bitmap(targetWidth, targetHeight);
int destWidth = (int)(sourceWidth * ratio);
int destHeight = (int)(sourceHeight * ratio);
int startX = 0;
int startY = 0;
if (destWidth < targetWidth)
startX = 0 + ((targetWidth - destWidth) / 2);
if (destHeight < targetHeight)
startY = 0 + ((targetHeight - destHeight) / 2);
newImage = new Bitmap(targetWidth, targetHeight);
using (Graphics graphics = Graphics.FromImage((System.Drawing.Image)newImage))
{
graphics.Clear(Color.Transparent);
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.DrawImage(image, startX, startY, destWidth, destHeight);
}
break;
}
}
return (System.Drawing.Image)newImage;
}
public void ProcessRequest(HttpContext context)
{
TimeSpan refresh = new TimeSpan(0, 15, 0);
context.Response.Cache.SetExpires(DateTime.Now.Add(refresh));
context.Response.Cache.SetMaxAge(refresh);
context.Response.Cache.SetCacheability(HttpCacheability.Public);
context.Response.CacheControl = HttpCacheability.Public.ToString();
context.Response.Cache.SetValidUntilExpires(true);
string currentPath = context.Server.MapPath(context.Request.Url.LocalPath);
string currentDirectory = Directory.GetParent(currentPath).ToString();
string img = !string.IsNullOrEmpty(context.Request.QueryString["Img"])
? Directory.GetParent(currentDirectory) + "\\Uploads\\" + context.Request.QueryString["Img"]
: currentDirectory + "\\NoImage.png";
string scale = !string.IsNullOrEmpty(context.Request.QueryString["Scale"])
? context.Request.QueryString["Scale"]
: "normal"; //giữ tỉ lệ
int width = !string.IsNullOrEmpty(context.Request.QueryString["W"])
? int.Parse(context.Request.QueryString["W"])
: 100;
int height = !string.IsNullOrEmpty(context.Request.QueryString["H"])
? int.Parse(context.Request.QueryString["H"])
: 100;
Resolution aResolution = new Resolution{
Width = width,
Height = height
};
Image imgToResize = File.Exists(img)
? Image.FromFile(img)
: Image.FromFile(currentDirectory + "\\NoImage.png");
switch (scale.ToLower()){
case "normal":
imgToResize = Resize(imgToResize, aResolution, ResizeMode.Normal);
break;
case "crop":
imgToResize = Resize(imgToResize, aResolution, ResizeMode.Crop);
break;
case "fill":
imgToResize = Resize(imgToResize, aResolution, ResizeMode.Fill);
break;
case "stretch":
imgToResize = Resize(imgToResize, aResolution, ResizeMode.Stretch);
break;
}
context.Response.ContentType = "image/jpeg";
imgToResize.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Png);
}
