public static Task <TResult> AnalyzeAsync <TResult>(this IRef <Content> contentRef,
Func <ImageAnalysis, double?, TResult> onAnalyzed,
Func <TResult> onNotFound = default)
{
return(AppSettings.CognitiveServices.ComputerVisionSubscriptionKey.ConfigurationString(
subscriptionKey =>
{
return AppSettings.CognitiveServices.ComputerVisionEndpoint.ConfigurationUri(
async endpointUri =>
{
using (var computerVision = new ComputerVisionClient(
new ApiKeyServiceClientCredentials(subscriptionKey),
new System.Net.Http.DelegatingHandler[] { }))
{
return await await contentRef.LoadStreamAsync(
async(imageStream, contentType) =>
{
var widthMultiplier = default(double?);
if (imageStream.Length > 4000000)
{
var image = System.Drawing.Image.FromStream(imageStream);
var newImageStream = new MemoryStream();
widthMultiplier = Math.Sqrt(4000000.0 / imageStream.Length);
image
.ResizeImage(
(int)(image.Width * widthMultiplier),
(int)(image.Height * widthMultiplier))
.Save(newImageStream, System.Drawing.Imaging.ImageFormat.Jpeg);
newImageStream.Position = 0;
imageStream = newImageStream;
}
computerVision.Endpoint = endpointUri.OriginalString;
var featuresToSearchFor = VisualFeatureTypes.Categories.AsArray()
.Append(VisualFeatureTypes.Description)
.Append(VisualFeatureTypes.ImageType)
.Append(VisualFeatureTypes.Objects)
.Append(VisualFeatureTypes.Tags)
.Append(VisualFeatureTypes.Brands)
.ToList();
try
{
var analysis = await computerVision.AnalyzeImageInStreamAsync(
imageStream, featuresToSearchFor);
return onAnalyzed(analysis, widthMultiplier);
}
catch (ComputerVisionErrorException ex)
{
throw ex;
}
},
() =>
{
if (onNotFound.IsDefaultOrNull())
{
throw new ResourceNotFoundException();
}
return onNotFound().AsTask();
});
}
});
}));
}
