public async Task CreateNewCompoundImage(Guid mapId, IList <Guid> imageIds)
{
var nextImageId = await _mapsAnalyser.SelectNextImageId(mapId, imageIds);
if (await CompoundImageAlreadyExists(mapId, imageIds))
{
return;
}
if (nextImageId == Guid.Empty)
{
return;
}
imageIds.Add(nextImageId);
var compoundImage = new CompoundImage {
MapId = mapId
};
await _compoundImagesRepository.InsertCompoundImage(compoundImage);
foreach (var imageId in imageIds)
{
await _compoundImageMappingsRepository.InsertCompoundImageMapping(imageId, compoundImage.Id);
}
var queueCompoundImage = new KeyedCompoundImage
{
CompoundImageId = compoundImage.Id,
ImageKey = await GetCompoundKeyFromImageIds(imageIds),
MapId = mapId,
Images = await GetCompoundImagePartsFromIds(imageIds)
};
await _queueAdapter.SendMessage(queueCompoundImage, "compound-image");
}
public Bitmap StitchImages(KeyedCompoundImage keyedCompoundImage)
{
// Set width and height assumming that every image has equal dimensions.
int width = 1000;
int height = 1000;
List <int> coordsX = new List <int>();
List <int> coordsY = new List <int>();
Bitmap compoundImage = null; // Final, stitched image
// Store coordinates of each image.
foreach (var image in keyedCompoundImage.Images)
{
coordsX.Add(image.Coordinate.X);
coordsY.Add(image.Coordinate.Y);
}
coordsX.Sort();
coordsY.Sort();
// Calculate canvas dimensions using the images count on each axis.
width *= coordsX[coordsX.Count - 1] - coordsX[0] + 1;
height *= coordsY[coordsY.Count - 1] - coordsY[0] + 1;
compoundImage = new Bitmap(width, height); // Initialise canvas with the dimensions.
// Get a graphics object from the image so we can draw on it.
using (Graphics g = Graphics.FromImage(compoundImage))
{
g.Clear(Color.Transparent); // Set the background color.
Bitmap bitmap;
var offsetX = 0;
var offsetY = 0;
// Go through each image and draw it on the _compoundImage.
foreach (var image in keyedCompoundImage.Images)
{
bitmap = CreateBitmapFromUrl(image.Image.Location);
offsetX = bitmap.Width * image.Coordinate.X - bitmap.Width;
offsetY = height - (bitmap.Height * image.Coordinate.Y - bitmap.Height) - bitmap.Height;
g.DrawImage(bitmap, new Rectangle(offsetX, offsetY, bitmap.Width, bitmap.Height));
bitmap.Dispose();
}
}
Stream compoundImageStream = new MemoryStream();
compoundImage.Save(compoundImageStream, ImageFormat.Jpeg);
// If stitched image is greater than 4MB in size...
if (compoundImageStream.Length > 400000)
{
// ...gradually decrease the image dimensions until it is less than 4MB in size (Azure Vision's limit).
do
{
compoundImageStream.Position = 0; // Rewind the memory stream.
compoundImage = ResizeImage(new Bitmap(compoundImageStream), Convert.ToInt32(compoundImage.Width * 0.9), Convert.ToInt32(compoundImage.Height * 0.9));
compoundImageStream.Position = 0;
compoundImage.Save(compoundImageStream, ImageFormat.Jpeg);
}while (compoundImageStream.Position > 400000);
return(compoundImage);
}
return(compoundImage);
}
