Un exemple ci-dessous d'une classe que j'ai faite qui resize toutes les images d'un dossier et les sauvegarde dans un autre. A vous de l'adapter :
public class ResizerService
{
public void ResizeFolder(string sourceFolder, string destinationFolder, int maxWidth, int maxHeight)
{
Parallel.ForEach(Directory.GetFiles(sourceFolder, "*.jpg"), fileName =>
{
var bmp = new Bitmap(fileName);
var exif = new EXIFextractor(ref bmp, "n"); // get source from http://www.codeproject.com/KB/graphics/exifextractor.aspx?fid=207371
var originalOrientation = OrientationToFlipType(exif["Orientation"]?.ToString());
var destFileName = Path.Combine(destinationFolder, Path.GetFileName(fileName));
Resize(fileName, destFileName, maxWidth, maxHeight);
if (originalOrientation != RotateFlipType.RotateNoneFlipNone)
{
bmp = new Bitmap(destFileName);
bmp.RotateFlip(originalOrientation);
bmp.Save(destFileName, ImageFormat.Jpeg);
}
});
}
public void Resize(string sourceFileName, string destinationFileName, int maxWidth, int maxHeight)
{
var baSource = File.ReadAllBytes(sourceFileName);
using (Stream mem = new MemoryStream(baSource))
{
var bmpFrame = ReadBitmapFrame(mem);
// To preserve the aspect ratio
var ratioX = maxWidth / (1d * bmpFrame.PixelWidth);
var ratioY = maxHeight / (1d * bmpFrame.PixelHeight);
var ratio = Math.Min(ratioX, ratioY);
// New width and height based on aspect ratio
var newWidth = (int)(bmpFrame.PixelWidth * ratio);
var newHeight = (int)(bmpFrame.PixelHeight * ratio);
var newBmpFrame = FastResize(bmpFrame, newWidth, newHeight);
var bmpResized = JpgToByteArray(newBmpFrame);
File.WriteAllBytes(destinationFileName, bmpResized);
}
}
private static BitmapFrame FastResize(BitmapSource bmpSource, int newWidth, int newHeight)
{
var bmp = new TransformedBitmap(bmpSource, new ScaleTransform(newWidth / (1d * bmpSource.PixelWidth), (1d * newHeight / bmpSource.PixelHeight), 0, 0));
return BitmapFrame.Create(bmp);
}
private static byte[] PngToByteArray(BitmapFrame bfResize)
{
using (var msStream = new MemoryStream())
{
var pbdDecoder = new PngBitmapEncoder();
pbdDecoder.Frames.Add(bfResize);
pbdDecoder.Save(msStream);
return msStream.ToArray();
}
}
private static byte[] JpgToByteArray(BitmapFrame bfResize)
{
using (var mem = new MemoryStream())
{
var encoder = new JpegBitmapEncoder {QualityLevel = 50};
encoder.Frames.Add(bfResize);
encoder.Save(mem);
return mem.ToArray();
}
}
private static BitmapFrame ReadBitmapFrame(Stream streamPhoto)
{
var bdDecoder = BitmapDecoder.Create(streamPhoto, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.None);
return bdDecoder.Frames[0];
}
private static RotateFlipType OrientationToFlipType(string orientation)
{
if (orientation == null)
return RotateFlipType.RotateNoneFlipNone;
switch (int.Parse(orientation))
{
case 1:
return RotateFlipType.RotateNoneFlipNone;
case 2:
return RotateFlipType.RotateNoneFlipX;
case 3:
return RotateFlipType.Rotate180FlipNone;
case 4:
return RotateFlipType.Rotate180FlipX;
case 5:
return RotateFlipType.Rotate90FlipX;
case 6:
return RotateFlipType.Rotate90FlipNone;
case 7:
return RotateFlipType.Rotate270FlipX;
case 8:
return RotateFlipType.Rotate270FlipNone;
default:
return RotateFlipType.RotateNoneFlipNone;
}
}
Richard Clark
Consultant - Formateur .NET
http://www.c2i.fr
Depuis 1996: le 1er site .NET francophone
