/// <summary>
/// Resizes an image to given size. The resized image will be saved to the given stream. Images that
/// are smaller than the requested target size will not be scaled up, but returned in original size.
/// </summary>
/// <param name="originalStream">Image to resize</param>
/// <param name="maxWidth">Maximum image width</param>
/// <param name="maxHeight">Maximum image height</param>
/// <param name="mediaType">MediaType</param>
/// <param name="fanArtType">FanArtType</param>
/// <param name="fanArtName">Fanart name</param>
/// <param name="originalFile">Original Filename</param>
/// <returns></returns>
protected static Stream ResizeImage(Stream originalStream, int maxWidth, int maxHeight, string originalFile)
{
if (maxWidth == 0 || maxHeight == 0)
{
return(originalStream);
}
try
{
if (!Directory.Exists(CACHE_PATH))
{
Directory.CreateDirectory(CACHE_PATH);
}
int maxSize = GetBestSupportedSize(maxWidth, maxHeight);
//Don't include the extension here, we support both jpg and png files, the CachedImageExists method will check with all supported extensions
string thumbFilenameWithoutExtension = Path.Combine(CACHE_PATH, string.Format("{0}x{1}_{2}", maxSize, maxSize, GetCrc32(originalFile)));
string cachedFilenameWithExtension;
if (CachedImageExists(thumbFilenameWithoutExtension, out cachedFilenameWithExtension))
{
using (originalStream)
return(new FileStream(cachedFilenameWithExtension, FileMode.Open, FileAccess.Read));
}
Image fullsizeImage = Image.FromStream(originalStream);
//Image doesn't need resizing, just return the original
if (fullsizeImage.Width <= maxSize && fullsizeImage.Height <= maxSize)
{
fullsizeImage.Dispose();
originalStream.Position = 0;
return(originalStream);
}
//Check whether the image has an alpha channel to determine whether to save it as a png or jpg
//Must be done before resizing as resizing disposes the fullsizeImage
bool isAlphaPixelFormat = Image.IsAlphaPixelFormat(fullsizeImage.PixelFormat);
MemoryStream resizedStream = new MemoryStream();
using (originalStream)
using (fullsizeImage)
using (Image newImage = ImageUtilities.ResizeImage(fullsizeImage, maxSize, maxSize))
{
if (isAlphaPixelFormat)
{
//Image supports an alpha channel, save as a png and add the appropriate extension
ImageUtilities.SavePng(thumbFilenameWithoutExtension + ".png", newImage);
ImageUtilities.SavePng(resizedStream, newImage);
}
else
{
//No alpha channel, save as a jpg and add the appropriate extension
ImageUtilities.SaveJpeg(thumbFilenameWithoutExtension + ".jpg", newImage, 95);
ImageUtilities.SaveJpeg(resizedStream, newImage, 95);
}
}
resizedStream.Position = 0;
return(resizedStream);
}
catch (Exception)
{
return(originalStream);
}
}
