protected override ResolveImageResult ResizeImpl(ResizeContext context, DimensionsContext dimensions)
{
var size = dimensions.Size;
var s = new SizeF(size.Width + 0.5f, size.Height + 0.5f).ToSize();
using (var bitmap = new Bitmap(s.Width, s.Height, PixelFormat.Format32bppArgb))
using (var graphics = Graphics.FromImage(bitmap))
{
graphics.Clear(Color.Transparent);
graphics.SmoothingMode = SmoothingMode.AntiAlias;
graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.DrawImage(Image, new Rectangle(0, 0, s.Width, s.Height), 0, 0, Image.Width, Image.Height, GraphicsUnit.Pixel);
var result = new MemoryStream();
bitmap.Save(result, ImageFormat.Png);
return new ResolveImageResult {Stream = result, MimeType = "image/png"};
}
}
protected override ResolveImageResult ResizeImpl(ResizeContext context, DimensionsContext dimensions)
{
//Cropping example: we have image 800x600, need to resize and crop it to 200x200.
//First we calculate size for this image, requirement here is to use entire area.
//So, in out example size will be 266,7x200. It is wider than required area -> image should be cropped
//Cropping is done by cloning the original image but only taking a rectangle of the original.
var size = dimensions.Size;
var s = new SizeF(size.Width + 0.5f, size.Height + 0.5f).ToSize();
using (var bitmap = new Bitmap(s.Width, s.Height, PixelFormat.Format32bppArgb))
using (var graphics = Graphics.FromImage(bitmap))
{
graphics.Clear(Color.Transparent);
graphics.SmoothingMode = SmoothingMode.AntiAlias;
graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.DrawImage(Image, new Rectangle(0, 0, s.Width, s.Height), 0, 0, Image.Width, Image.Height, GraphicsUnit.Pixel);
var result = new MemoryStream();
var offsetX = Math.Max(0, (bitmap.Width - context.Width)/2);
var offsetY = Math.Max(0, (bitmap.Height - context.Height)/2);
var offset = context.Center ? new Point(offsetX, offsetY) : new Point(0, 0);
using (var cropped = bitmap.Clone(new Rectangle(offset.X, offset.Y, context.Width, context.Height), bitmap.PixelFormat))
{
cropped.Save(result, ImageFormat.Png);
}
return new ResolveImageResult {Stream = result, MimeType = "image/png"};
}
}
public ResolveImageResult Resize(ResizeContext context)
{
var halfWidth = 0.5f * Image.Width;
var halfHeight = 0.5f * Image.Height;
var points = new[]
{
new PointF(-halfWidth, -halfHeight), new PointF(+halfWidth, -halfHeight),
new PointF(+halfWidth, +halfHeight), new PointF(-halfWidth, +halfHeight)
};
var matrix = new Matrix();
matrix.TransformPoints(points);
var min = new PointF(+float.MaxValue, +float.MaxValue);
var max = new PointF(-float.MaxValue, -float.MaxValue);
foreach (var point in points)
{
if (min.X > point.X) min.X = point.X;
if (min.Y > point.Y) min.Y = point.Y;
if (max.X < point.X) max.X = point.X;
if (max.Y < point.Y) max.Y = point.Y;
}
var width = (float)Math.Ceiling(max.X - min.X);
var height = (float)Math.Ceiling(max.Y - min.Y);
float scale;
var size = CalculateSize(new SizeF(width, height), new SizeF(context.Width, context.Height), out scale);
var dimensions = new DimensionsContext {Size = size, Scale = scale, Points = points, Max = max, Min = min};
return ResizeImpl(context, dimensions);
}
protected abstract ResolveImageResult ResizeImpl(ResizeContext context, DimensionsContext dimensions);
protected override ResolveImageResult ResizeImpl(ResizeContext context, DimensionsContext dimensions)
{
var size = dimensions.Size;
var scale = dimensions.Scale;
var points = dimensions.Points;
var min = dimensions.Min;
// var max = dimensions.Max;
var dx = 0.5f * (Image.Width - size.Width);
var dy = 0.5f * (context.Height - size.Height);
using (var bitmap = new Bitmap(Image.Width, context.Height, PixelFormat.Format32bppArgb))
using (var graphics = Graphics.FromImage(bitmap))
{
graphics.Clear(Color.Transparent);
graphics.SmoothingMode = SmoothingMode.AntiAlias;
graphics.CompositingQuality = CompositingQuality.HighQuality;
graphics.InterpolationMode = InterpolationMode.High;
Point[] destination =
{
Point.Round(new PointF((points[0].X - min.X)*scale + dx, (points[0].Y - min.Y)*scale + dy)),
Point.Round(new PointF((points[1].X - min.X)*scale + dx, (points[1].Y - min.Y)*scale + dy)),
Point.Round(new PointF((points[3].X - min.X)*scale + dx, (points[3].Y - min.Y)*scale + dy))
};
graphics.DrawImage(Image, destination);
var result = new MemoryStream();
bitmap.Save(result, ImageFormat.Png);
return new ResolveImageResult { Stream = result, MimeType = "image/png" };
}
}
