public static async Task GenerateMosaicFromTilesAsync(
Stream sourceImage,
CloudBlobContainer tileContainer, string tileDirectory,
Stream outputStream,
int tilePixels,
TraceWriter log)
{
using (var tileProvider = new QuadrantMatchingTileProvider()) {
MosaicBuilder.TileHeight = int.Parse(Environment.GetEnvironmentVariable("MosaicTileWidth"));
MosaicBuilder.TileWidth = int.Parse(Environment.GetEnvironmentVariable("MosaicTileHeight"));
// override default tile width and height if specified
if (tilePixels != 0)
{
MosaicBuilder.TileWidth = MosaicBuilder.TileHeight = tilePixels;
}
MosaicBuilder.DitheringRadius = -1;
MosaicBuilder.ScaleMultiplier = 1;
List <byte[]> tileImages = await GetTileImagesAsync(tileContainer, tileDirectory, log);
tileProvider.SetSourceStream(sourceImage);
tileProvider.ProcessInputImageColors(MosaicBuilder.TileWidth, MosaicBuilder.TileHeight);
tileProvider.ProcessTileColors(tileImages);
log.Info("Generating mosaic...");
var start = DateTime.Now;
GenerateMosaic(tileProvider, sourceImage, tileImages, outputStream);
log.Info($"Time to generate mosaic: {(DateTime.Now - start).TotalMilliseconds}");
}
}
public static void GenerateMosaicFromTiles(
Stream sourceImage, CloudBlobContainer tileContainer, string tileDirectory, Stream outputStream)
{
using (var tileProvider = new QuadrantMatchingTileProvider()) {
MosaicBuilder.TileHeight = int.Parse(Environment.GetEnvironmentVariable("MosaicTileWidth"));
MosaicBuilder.TileWidth = int.Parse(Environment.GetEnvironmentVariable("MosaicTileHeight"));
MosaicBuilder.DitheringRadius = -1;
MosaicBuilder.ScaleMultiplier = 1;
var directory = tileContainer.GetDirectoryReference(tileDirectory);
var blobs = directory.ListBlobs(true);
var tileImages = new List <byte[]>();
foreach (var b in blobs)
{
if (b.GetType() == typeof(CloudBlockBlob))
{
var blob = (CloudBlockBlob)b;
blob.FetchAttributes();
var bytes = new byte[blob.Properties.Length];
blob.DownloadToByteArray(bytes, 0);
tileImages.Add(bytes);
}
}
tileProvider.SetSourceStream(sourceImage);
tileProvider.ProcessInputImageColors(MosaicBuilder.TileWidth, MosaicBuilder.TileHeight);
tileProvider.ProcessTileColors(tileImages);
GenerateMosaic(tileProvider, sourceImage, tileImages, outputStream);
}
}
private static void GenerateMosaic(QuadrantMatchingTileProvider tileProvider, Stream inputStream, List <byte[]> tileImages, Stream outputStream)
{
SKBitmap[,] mosaicTileGrid;
inputStream.Seek(0, SeekOrigin.Begin);
using (var skStream = new SKManagedStream(inputStream))
using (var bitmap = SKBitmap.Decode(skStream)) {
// use transparency for the source image overlay
var srcImagePaint = new SKPaint()
{
Color = SKColors.White.WithAlpha(200)
};
int xTileCount = bitmap.Width / MosaicBuilder.TileWidth;
int yTileCount = bitmap.Height / MosaicBuilder.TileHeight;
int tileCount = xTileCount * yTileCount;
mosaicTileGrid = new SKBitmap[xTileCount, yTileCount];
int finalTileWidth = MosaicBuilder.TileWidth * MosaicBuilder.ScaleMultiplier;
int finalTileHeight = MosaicBuilder.TileHeight * MosaicBuilder.ScaleMultiplier;
int targetWidth = xTileCount * finalTileWidth;
int targetHeight = yTileCount * finalTileHeight;
var tileList = new List <(int, int)>();
// add coordinates for the left corner of each tile
for (int x = 0; x < xTileCount; x++)
{
for (int y = 0; y < yTileCount; y++)
{
tileList.Add((x, y));
}
}
// create output surface
var surface = SKSurface.Create(targetWidth, targetHeight, SKImageInfo.PlatformColorType, SKAlphaType.Premul);
surface.Canvas.DrawColor(SKColors.White); // clear the canvas / fill with white
surface.Canvas.DrawBitmap(bitmap, 0, 0, srcImagePaint);
// using the Darken blend mode causes colors from the source image to come through
var tilePaint = new SKPaint()
{
BlendMode = SKBlendMode.Darken
};
surface.Canvas.SaveLayer(tilePaint); // save layer so blend mode is applied
var random = new Random();
while (tileList.Count > 0)
{
// choose a new tile at random
int nextIndex = random.Next(tileList.Count);
var tileInfo = tileList[nextIndex];
tileList.RemoveAt(nextIndex);
// get the tile image for this point
//var exclusionList = GetExclusionList(mosaicTileGrid, tileInfo.Item1, tileInfo.Item2);
var tileBitmap = tileProvider.GetImageForTile(tileInfo.Item1, tileInfo.Item2);
mosaicTileGrid[tileInfo.Item1, tileInfo.Item2] = tileBitmap;
// draw the tile on the surface at the coordinates
SKRect tileRect = SKRect.Create(tileInfo.Item1 * TileWidth, tileInfo.Item2 * TileHeight, finalTileWidth, finalTileHeight);
surface.Canvas.DrawBitmap(tileBitmap, tileRect);
}
surface.Canvas.Restore(); // merge layers
surface.Canvas.Flush();
var imageBytes = surface.Snapshot().Encode(SKEncodedImageFormat.Jpeg, 80);
imageBytes.SaveTo(outputStream);
}
}
