/// <summary>
/// Opens the image stream to read. If the <paramref name="maxSize"/> is not null, it will
/// also resize the image if it is larger than the max Size.
/// </summary>
/// <param name="image">The image to read.</param>
/// <param name="maxSize">The optional maximum image's dimension.</param>
/// <returns></returns>
protected virtual Stream OpenRead(ImageQueue image, Size?maxSize = null)
{
var blobContainer = _blobService.Get(image.BlobUri);
var blobStream = blobContainer.GetDefault().OpenRead();
if (!maxSize.HasValue)
{
return(blobStream);
}
return(EnsureMaxImageSize(blobStream, maxSize.Value, image));
}
protected virtual Stream EnsureMaxImageSize(Stream blobStream, Size maxSize, ImageQueue image)
{
using (var bitmap = Image.FromStream(blobStream))
{
// if the image's dimension if larger than max size, we resize it to:
// save the bandwidth
// and also to prevent any quota/litmitation error might have
if (bitmap.Width > maxSize.Width || bitmap.Height > maxSize.Height)
{
double heightWidthRatio = ((double)bitmap.Height) / bitmap.Width;
var newSize = new Size(maxSize.Width, Convert.ToInt32(maxSize.Width * heightWidthRatio));
if (newSize.Height > maxSize.Height)
{
newSize = new Size(Convert.ToInt32(maxSize.Height / heightWidthRatio), maxSize.Height);
}
var imageFormat = FileExtensions.GetImageFormat(_mimeExtensionHelper.FindMime(Path.GetExtension(image.FileName)), true);
return(_imageResizer.Resize(newSize, true, blobStream, imageFormat).Result);
}
return(blobStream);
}
}
