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using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
namespace MediaBrowser.Api
{
public static class ImageProcessor
{
public static void ProcessImage(string path, Stream toStream, int? width, int? height, int? maxWidth, int? maxHeight, int? quality)
{
Image originalImage = Image.FromFile(path);
var newWidth = originalImage.Width;
var newHeight = originalImage.Height;
if (width.HasValue && height.HasValue)
{
newWidth = width.Value;
newHeight = height.Value;
}
else if (height.HasValue)
{
newWidth = GetNewWidth(newHeight, newWidth, height.Value);
newHeight = height.Value;
}
else if (width.HasValue)
{
newHeight = GetNewHeight(newHeight, newWidth, width.Value);
newWidth = width.Value;
}
if (maxHeight.HasValue && maxHeight < newHeight)
{
newWidth = GetNewWidth(newHeight, newWidth, maxHeight.Value);
newHeight = maxHeight.Value;
}
if (maxWidth.HasValue && maxWidth < newWidth)
{
newHeight = GetNewHeight(newHeight, newWidth, maxWidth.Value);
newWidth = maxWidth.Value;
}
Bitmap thumbnail = new Bitmap(newWidth, newHeight, originalImage.PixelFormat);
thumbnail.SetResolution(originalImage.HorizontalResolution, originalImage.VerticalResolution);
Graphics thumbnailGraph = Graphics.FromImage(thumbnail);
thumbnailGraph.CompositingQuality = CompositingQuality.HighQuality;
thumbnailGraph.SmoothingMode = SmoothingMode.HighQuality;
thumbnailGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;
thumbnailGraph.PixelOffsetMode = PixelOffsetMode.HighQuality;
thumbnailGraph.CompositingMode = CompositingMode.SourceOver;
thumbnailGraph.DrawImage(originalImage, 0, 0, newWidth, newHeight);
Write(originalImage, thumbnail, toStream, quality);
thumbnailGraph.Dispose();
thumbnail.Dispose();
originalImage.Dispose();
}
private static void Write(Image originalImage, Image newImage, Stream toStream, int? quality)
{
// Use special save methods for jpeg and png that will result in a much higher quality image
// All other formats use the generic Image.Save
if (ImageFormat.Jpeg.Equals(originalImage.RawFormat))
{
SaveJpeg(newImage, toStream, quality);
}
else if (ImageFormat.Png.Equals(originalImage.RawFormat))
{
SavePng(newImage, toStream);
}
else
{
newImage.Save(toStream, originalImage.RawFormat);
}
}
private static void SaveJpeg(Image newImage, Stream target, int? quality)
{
if (!quality.HasValue)
{
quality = 90;
}
using (EncoderParameters encoderParameters = new EncoderParameters(1))
{
encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, quality.Value);
newImage.Save(target, GetImageCodeInfo("image/jpeg"), encoderParameters);
}
}
private static void SavePng(Image newImage, Stream target)
{
if (target.CanSeek)
{
newImage.Save(target, ImageFormat.Png);
}
else
{
using (MemoryStream ms = new MemoryStream(4096))
{
newImage.Save(ms, ImageFormat.Png);
ms.WriteTo(target);
}
}
}
private static ImageCodecInfo GetImageCodeInfo(string mimeType)
{
ImageCodecInfo[] info = ImageCodecInfo.GetImageEncoders();
for (int i = 0; i < info.Length; i++)
{
ImageCodecInfo ici = info[i];
if (ici.MimeType.Equals(mimeType, StringComparison.OrdinalIgnoreCase))
{
return ici;
}
}
return info[1];
}
private static int GetNewWidth(int currentHeight, int currentWidth, int newHeight)
{
decimal scaleFactor = newHeight;
scaleFactor /= currentHeight;
scaleFactor *= currentWidth;
return Convert.ToInt32(scaleFactor);
}
private static int GetNewHeight(int currentHeight, int currentWidth, int newWidth)
{
decimal scaleFactor = newWidth;
scaleFactor /= currentWidth;
scaleFactor *= currentHeight;
return Convert.ToInt32(scaleFactor);
}
}
}
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