private async Task<byte[]> ImageToBytes(IRandomAccessStream sourceStream)
{
byte[] imageArray;
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(sourceStream);
var transform = new BitmapTransform { ScaledWidth = decoder.PixelWidth, ScaledHeight = decoder.PixelHeight };
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.DoNotColorManage);
using (var destinationStream = new InMemoryRandomAccessStream())
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, destinationStream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Premultiplied, decoder.PixelWidth,
decoder.PixelHeight, 96, 96, pixelData.DetachPixelData());
await encoder.FlushAsync();
BitmapDecoder outputDecoder = await BitmapDecoder.CreateAsync(destinationStream);
await destinationStream.FlushAsync();
imageArray = (await outputDecoder.GetPixelDataAsync()).DetachPixelData();
}
return imageArray;
}
public static async Task<Color> GetDominantColorFromFile(StorageFile file)
{
//get the file
using (var stream = await file.OpenAsync(FileAccessMode.Read))
{
//Create a decoder for the image
var decoder = await BitmapDecoder.CreateAsync(stream);
//Create a transform to get a 1x1 image
var myTransform = new BitmapTransform { ScaledHeight = 1, ScaledWidth = 1 };
//Get the pixel provider
var pixels = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Ignore,
myTransform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.DoNotColorManage);
//Get the bytes of the 1x1 scaled image
var bytes = pixels.DetachPixelData();
//read the color
var myDominantColor = Color.FromArgb(255, bytes[0], bytes[1], bytes[2]);
return myDominantColor;
}
}
/// <summary>
/// Use BitmapTransform to define the region to crop, and then get the pixel data in the region.
/// If you want to get the pixel data of a scaled image, set the scaledWidth and scaledHeight
/// of the scaled image.
/// </summary>
/// <returns></returns>
async static private Task<byte[]> GetPixelData(BitmapDecoder decoder, uint startPointX, uint startPointY,
uint width, uint height, uint scaledWidth, uint scaledHeight)
{
BitmapTransform transform = new BitmapTransform();
BitmapBounds bounds = new BitmapBounds();
bounds.X = startPointX;
bounds.Y = startPointY;
bounds.Height = height;
bounds.Width = width;
transform.Bounds = bounds;
transform.ScaledWidth = scaledWidth;
transform.ScaledHeight = scaledHeight;
// Get the cropped pixels within the bounds of transform.
PixelDataProvider pix = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.ColorManageToSRgb);
byte[] pixels = pix.DetachPixelData();
return pixels;
}
public async Task ConverterBitmapToTargetStreamAsync(IRandomAccessStream bitmapSourceStream, IRandomAccessStream saveTargetStream)
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(bitmapSourceStream);
// Scale image to appropriate size
BitmapTransform transform = new BitmapTransform()
{
//ScaledWidth = Convert.ToUInt32(bi.PixelWidth),
//ScaledHeight = Convert.ToUInt32(bi.PixelHeight)
};
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8, // WriteableBitmap uses BGRA format
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.RespectExifOrientation, // This sample ignores Exif orientation
ColorManagementMode.DoNotColorManage);
var BitmapEncoderGuid = BitmapEncoder.PngEncoderId;
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoderGuid, saveTargetStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore,
(uint)decoder.PixelWidth,
(uint)decoder.PixelHeight,
96.0,
96.0,
pixelData.DetachPixelData());
await encoder.FlushAsync();
}
async Task<WriteableBitmap> ResizeImage(WriteableBitmap baseWriteBitmap, uint width, uint height)
{
Stream stream = baseWriteBitmap.PixelBuffer.AsStream();
byte[] pixels = new byte[(uint)stream.Length];
await stream.ReadAsync(pixels, 0, pixels.Length);
var inMemoryRandomStream = new InMemoryRandomAccessStream();
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, inMemoryRandomStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore, (uint)baseWriteBitmap.PixelWidth, (uint)baseWriteBitmap.PixelHeight, 96, 96, pixels);
await encoder.FlushAsync();
var transform = new BitmapTransform
{
ScaledWidth = width,
ScaledHeight = height
};
inMemoryRandomStream.Seek(0);
var decoder = await BitmapDecoder.CreateAsync(inMemoryRandomStream);
var pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.DoNotColorManage);
var sourceDecodedPixels = pixelData.DetachPixelData();
var inMemoryRandomStream2 = new InMemoryRandomAccessStream();
var encoder2 = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, inMemoryRandomStream2);
encoder2.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore, width, height, 96, 96, sourceDecodedPixels);
await encoder2.FlushAsync();
inMemoryRandomStream2.Seek(0);
var bitmap = new WriteableBitmap((int)width, (int)height);
await bitmap.SetSourceAsync(inMemoryRandomStream2);
return bitmap;
}
private static async Task<WriteableBitmap> read()
{
using (IRandomAccessStream stream = await file.OpenAsync(FileAccessMode.Read))
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(BitmapDecoder.JpegDecoderId, stream);
uint width = decoder.PixelWidth;
uint height = decoder.PixelHeight;
if (angle % 180 != 0)
{
width = decoder.PixelHeight;
height = decoder.PixelWidth;
}
Dictionary<int, BitmapRotation> angles = new Dictionary<int, BitmapRotation>()
{
{ 0, BitmapRotation.None },
{ 90, BitmapRotation.Clockwise90Degrees },
{ 180, BitmapRotation.Clockwise180Degrees },
{ 270, BitmapRotation.Clockwise270Degrees },
{ 360, BitmapRotation.None }
};
BitmapTransform transform = new BitmapTransform();
transform.Rotation = angles[angle];
PixelDataProvider data = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore, transform,
ExifOrientationMode.IgnoreExifOrientation, ColorManagementMode.DoNotColorManage);
bitmap = new WriteableBitmap((int)width, (int)height);
byte[] buffer = data.DetachPixelData();
using (Stream pixels = bitmap.PixelBuffer.AsStream())
{
pixels.Write(buffer, 0, (int)pixels.Length);
}
}
return bitmap;
}
private async void OnClick(object sender, RoutedEventArgs e)
{
Button btn = sender as Button;
btn.IsEnabled = false;
// 项目中的图像文件
Uri gifUri = new Uri("ms-appx:///Assets/1.gif");
StorageFile gifFile = await StorageFile.GetFileFromApplicationUriAsync(gifUri);
using (IRandomAccessStream inputStream = await gifFile.OpenReadAsync()) // 打开文件流
{
// 创建图像解码器实例
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(BitmapDecoder.GifDecoderId, inputStream);
// 获取图像文件中的总帧数
uint frameCount = decoder.FrameCount;
// 分别读取各个帧中的图像，并添加到 ListView 控件中
for(uint n = 0; n < frameCount; ++n)
{
BitmapFrame curFrame = await decoder.GetFrameAsync(n);
// 获取图像的像素数据
// 在获取数据时，对图像进行变换处理
// 将宽度和高度变为原来的 1/3
BitmapTransform btf = new BitmapTransform();
btf.ScaledWidth = curFrame.PixelWidth / 3;
btf.ScaledHeight = curFrame.PixelHeight / 3;
var pxprd = await curFrame.GetPixelDataAsync(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Straight, btf, ExifOrientationMode.IgnoreExifOrientation, ColorManagementMode.DoNotColorManage);
byte[] data = pxprd.DetachPixelData();
// 创建内存位图图像
WriteableBitmap bmp = new WriteableBitmap((int)btf.ScaledWidth, (int)btf.ScaledHeight);
data.CopyTo(bmp.PixelBuffer);
lvimgs.Items.Add(bmp);
}
}
btn.IsEnabled = true;
}
/// <summary>
/// This function rotates the passed WriteableBitmap clockwise or counter-clockwise
/// </summary>
/// <param name="baseWriteBitmap"> WriteableBitmap to be rotated </param>
/// <param name="width"> Width of the WriteableBitmap </param>
/// <param name="height"> Height of the WriteableBitmap </param>
/// <param name="position"> If 'right', it rotates clockwise, if 'left' - counterclockwise </param>
public async Task<WriteableBitmap> RotateImage(WriteableBitmap baseWriteBitmap, uint width, uint height, string position)
{
// Get the pixel buffer of the writable bitmap in bytes
Stream stream = baseWriteBitmap.PixelBuffer.AsStream();
byte[] pixels = new byte[(uint)stream.Length];
await stream.ReadAsync(pixels, 0, pixels.Length);
//Encoding the data of the PixelBuffer we have from the writable bitmap
var inMemoryRandomStream = new InMemoryRandomAccessStream();
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, inMemoryRandomStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore, (uint)baseWriteBitmap.PixelWidth, (uint)baseWriteBitmap.PixelHeight, 96, 96, pixels);
await encoder.FlushAsync();
// At this point we have an encoded image in inMemoryRandomStream
// We apply the transform and decode
BitmapRotation rotateTo = BitmapRotation.None;
if (position == "right")
{
rotateTo = BitmapRotation.Clockwise90Degrees;
}
else if (position == "left")
{
rotateTo = BitmapRotation.Clockwise270Degrees;
}
var transform = new BitmapTransform
{
ScaledWidth = width,
ScaledHeight = height,
Rotation = rotateTo
};
inMemoryRandomStream.Seek(0);
var decoder = await BitmapDecoder.CreateAsync(inMemoryRandomStream);
var pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.DoNotColorManage);
// An array containing the decoded image data
var sourceDecodedPixels = pixelData.DetachPixelData();
// We encode the image buffer again:
// Encoding data
var inMemoryRandomStream2 = new InMemoryRandomAccessStream();
var encoder2 = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, inMemoryRandomStream2);
encoder2.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore, height, width, 96, 96, sourceDecodedPixels);
await encoder2.FlushAsync();
inMemoryRandomStream2.Seek(0);
// Finally the resized WritableBitmap
var bitmap = new WriteableBitmap((int)width, (int)height);
await bitmap.SetSourceAsync(inMemoryRandomStream2);
return bitmap;
}
/// <summary>
/// 改变图片大小
/// </summary>
/// <param name="sourceStream">包含图片数据的数据流</param>
/// <param name="scaleLong">如果图片长大于宽，那么此为改编后的长度，反之是改变后的高度</param>
/// <returns></returns>
public static async Task<IRandomAccessStream> ResizeImage(IRandomAccessStream sourceStream,uint scaleLong)
{
try
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(sourceStream);
uint height = decoder.PixelHeight;
uint weight = decoder.PixelWidth;
double rate;
uint destHeight = height;
uint destWeight = weight;
if (weight > height)
{
rate = scaleLong / (double)weight;
destHeight = weight > scaleLong ? (uint)(rate * height) : height;
destWeight = scaleLong;
}
else
{
rate = scaleLong / (double)height;
destWeight = height > scaleLong ? (uint)(rate * weight) : weight;
destHeight = scaleLong;
}
BitmapTransform transform = new BitmapTransform()
{
ScaledWidth = destWeight,
ScaledHeight = destHeight
};
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.DoNotColorManage);
var folder = ApplicationData.Current.TemporaryFolder;
var tempfile = await folder.CreateFileAsync("temp.jpg", CreationCollisionOption.GenerateUniqueName);
IRandomAccessStream destStream = await tempfile.OpenAsync(FileAccessMode.ReadWrite);
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, destStream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, transform.ScaledWidth, transform.ScaledHeight, 100, 100, pixelData.DetachPixelData());
await encoder.FlushAsync();
//REMEMBER
destStream.Seek(0);
await tempfile.DeleteAsync(StorageDeleteOption.PermanentDelete);
return destStream;
}
catch(Exception e)
{
var task = ExceptionHelper.WriteRecordAsync(e, nameof(BitmapHandleHelper), nameof(ResizeImage));
return null;
}
}
private async Task<BitmapSource> resize(int width, int height, Windows.Storage.Streams.IRandomAccessStream source)
{
WriteableBitmap small = new WriteableBitmap(width, height);
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(source);
BitmapTransform transform = new BitmapTransform();
transform.ScaledHeight = (uint)height; transform.ScaledWidth = (uint)width;
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Straight, transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.DoNotColorManage);
pixelData.DetachPixelData().CopyTo(small.PixelBuffer);
return small;
}
/// <summary>
/// 异步从网络下载图片
/// </summary>
/// <param name="outfileName">下载保存到本地的图片文件名</param>
/// <param name="downloadUriString">图片uri</param>
/// <param name="scaleSize">图片尺寸</param>
/// <returns></returns>
public static async Task DownloadAndScale(string outfileName, string downloadUriString, Size scaleSize)
{
try
{
Uri downLoadingUri = new Uri(downloadUriString); //创建uri对象
HttpClient client = new HttpClient(); //实例化httpclient对象
using (var response = await client.GetAsync(downLoadingUri))
{
var buffer = await response.Content.ReadAsBufferAsync();//从返回的数据中读取buffer
var memoryStream = new InMemoryRandomAccessStream();
await memoryStream.WriteAsync(buffer); //将buffer写入memorystream
await memoryStream.FlushAsync(); //刷新
var decoder = await Windows.Graphics.Imaging.BitmapDecoder.CreateAsync(memoryStream); //解密文件流
//确定图片大小
var bt = new Windows.Graphics.Imaging.BitmapTransform();
bt.ScaledWidth = (uint)scaleSize.Width;
bt.ScaledHeight = (uint)scaleSize.Height;
//得到像素数值
var pixelProvider = await decoder.GetPixelDataAsync(
decoder.BitmapPixelFormat, decoder.BitmapAlphaMode, bt,
ExifOrientationMode.IgnoreExifOrientation, ColorManagementMode.ColorManageToSRgb);
//下面保存图片
// Now that we have the pixel data, get the destination file
var localFolder = ApplicationData.Current.LocalFolder;
//var resultsFolder = await localFolder.CreateFolderAsync("Results", CreationCollisionOption.OpenIfExists);
var scaledFile = await localFolder.CreateFileAsync(outfileName, CreationCollisionOption.ReplaceExisting);
using (var scaledFileStream = await scaledFile.OpenAsync(FileAccessMode.ReadWrite))
{
var encoder = await BitmapEncoder.CreateAsync(
BitmapEncoder.JpegEncoderId, scaledFileStream);
var pixels = pixelProvider.DetachPixelData();
encoder.SetPixelData(
decoder.BitmapPixelFormat,
decoder.BitmapAlphaMode,
(uint)scaleSize.Width,
(uint)scaleSize.Height,
decoder.DpiX,
decoder.DpiY,
pixels
);
await encoder.FlushAsync();
}
}
}
catch (Exception) { Debug.WriteLine("工具，图片异常"); }
}
/// <summary>
/// IRandomAccessStreamからWriteableBitmapを生成する
/// </summary>
/// <param name="stream">ランダムアクセスストリーム</param>
/// <returns>WriteableBitmapオブジェクト</returns>
public static async Task<WriteableBitmap> FromStreamAsync(IRandomAccessStream stream)
{
// ストリームからピクセルデータを読み込む
var decoder = await BitmapDecoder.CreateAsync(stream);
var transform = new BitmapTransform();
var pixelData = await decoder.GetPixelDataAsync(decoder.BitmapPixelFormat, decoder.BitmapAlphaMode,
transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.ColorManageToSRgb);
var pixels = pixelData.DetachPixelData();
// ピクセルデータからWriteableBitmapオブジェクトを生成する
return WriteableBitmapExtensions.FromArray((int)decoder.OrientedPixelWidth, (int)decoder.OrientedPixelHeight, pixels);
}
public async Task SaveBitmapAsync(string albumFolder, uint size, string songPath)
{
var songFile = await StorageFile.GetFileFromPathAsync(songPath);
using (var thumbnail = await songFile.GetThumbnailAsync(ThumbnailMode.MusicView, size) ??
await songFile.GetThumbnailAsync(ThumbnailMode.VideosView, size))
{
if (thumbnail == null)
return;
var reader = new DataReader(thumbnail);
var fileLength = (uint)thumbnail.Size;
await reader.LoadAsync(fileLength);
var buffer = reader.ReadBuffer(fileLength);
var memStream = new InMemoryRandomAccessStream();
await memStream.WriteAsync(buffer);
await memStream.FlushAsync();
memStream.Seek(0);
await ApplicationData.Current.LocalFolder.CreateFolderAsync(AlbumArtFolderName(albumFolder), CreationCollisionOption.OpenIfExists);
var albumArtFileName = AlbumArtFileName(albumFolder, size);
var outputFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(albumArtFileName, CreationCollisionOption.ReplaceExisting);
// http://social.msdn.microsoft.com/Forums/windowsapps/en-US/1dda3a15-d299-40e0-b668-ec690a683f6e/how-to-resize-an-image-as-storagefile?forum=winappswithcsharp
var decoder = await BitmapDecoder.CreateAsync(memStream);
var transform = new BitmapTransform { ScaledHeight = size, ScaledWidth = size };
var pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.DoNotColorManage);
using (var destinationStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, destinationStream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Premultiplied, size, size, 96, 96, pixelData.DetachPixelData());
await encoder.FlushAsync();
}
}
}
public async Task WriteImageAsync(IRandomAccessStream sourceStream, string filename)
{
// 维持横纵比的重置图像大小
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(sourceStream);
uint scaledWidth = 0;
uint scaledHeight = 0;
if (decoder.PixelWidth > decoder.PixelHeight)
{
scaledWidth = 600;
double relation = (double)decoder.PixelHeight / decoder.PixelWidth;
scaledHeight = Convert.ToUInt32(relation * scaledWidth);
}
else
{
scaledHeight = 600;
double relation = decoder.PixelWidth / decoder.PixelHeight;
scaledWidth = Convert.ToUInt32(relation * scaledHeight);
}
var transform = new BitmapTransform() { ScaledWidth = scaledWidth, ScaledHeight = scaledHeight };
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.DoNotColorManage);
var folder = ApplicationData.Current.RoamingFolder;
StorageFile destinationFile = await folder.CreateFileAsync(filename);
using (var destinationStream = await destinationFile.OpenAsync(
FileAccessMode.ReadWrite))
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(
BitmapEncoder.PngEncoderId, destinationStream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Premultiplied,
scaledWidth, scaledHeight, 96, 96, pixelData.DetachPixelData());
await encoder.FlushAsync();
}
}
public static async Task<Color> GetDominantColorAsync(this DataModel.Api.Image entity)
{
using (var ms = new InMemoryRandomAccessStream())
{
using (var writer = new DataWriter(ms.GetOutputStreamAt(0)))
{
writer.WriteBytes(entity.Content);
writer.StoreAsync().GetResults();
}
var decoder = await BitmapDecoder.CreateAsync(ms);
var myTransform = new BitmapTransform { ScaledHeight = 1, ScaledWidth = 1 };
var pixels = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Ignore,
myTransform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.DoNotColorManage);
var bytes = pixels.DetachPixelData();
return Color.FromArgb(255, bytes[0], bytes[1], bytes[2]);
}
}
/// <summary>
/// Resizes the image presented by the <paramref name="imageData"/> to a <paramref name="newSize"/>.
/// </summary>
/// <param name="imageData">
/// The binary data of the image to resize.
/// </param>
/// <param name="newSize">
/// The size to which to resize the image.
/// </param>
/// <param name="keepAspectRatio">
/// A flag indicating whether to save original aspect ratio.
/// </param>
/// <returns>
/// The structure which contains binary data of resized image and the actial size of resized image depending on <paramref name="keepAspectRatio"/> value.
/// </returns>
public static async Task<ImageInfo> ResizeAsync(this byte[] imageData, Size newSize, bool keepAspectRatio)
{
var result = new ImageInfo();
var decoder = await BitmapDecoder.CreateAsync(await imageData.AsRandomAccessStreamAsync());
var percentWidth = (double)newSize.Width / (double)decoder.PixelWidth;
var percentHeight = (double)newSize.Height / (double)decoder.PixelHeight;
if (keepAspectRatio)
{
result.Size = percentWidth < percentHeight
? new Size(newSize.Width, (int)(decoder.PixelHeight * percentWidth))
: new Size((int)(decoder.PixelWidth * percentHeight), newSize.Height);
}
else
{
result.Size = newSize;
}
var transform = new BitmapTransform { ScaledWidth = (uint)result.Size.Width, ScaledHeight = (uint)result.Size.Height };
var pixelData = await decoder.GetPixelDataAsync(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.DoNotColorManage);
using (var destinationStream = new InMemoryRandomAccessStream())
{
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, destinationStream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Premultiplied, (uint)result.Size.Width, (uint)result.Size.Height, 96, 96, pixelData.DetachPixelData());
await encoder.FlushAsync();
var data = new byte[destinationStream.Size];
destinationStream.Seek(0);
await destinationStream.ReadAsync(data.AsBuffer(), (uint)destinationStream.Size, InputStreamOptions.None);
result.Data = data;
}
return result;
}
protected override async void init(Stream stream, bool flip, Loader.LoadedCallbackMethod loadedCallback)
{
try
{
using (var memoryStream = new InMemoryRandomAccessStream())
{
await RandomAccessStream.CopyAsync(stream.AsInputStream(), memoryStream);
var decoder = await BitmapDecoder.CreateAsync(memoryStream);
var frame = await decoder.GetFrameAsync(0);
var transform = new BitmapTransform();
transform.InterpolationMode = BitmapInterpolationMode.NearestNeighbor;
transform.Rotation = BitmapRotation.None;
var dataProvider = await decoder.GetPixelDataAsync(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, transform, ExifOrientationMode.IgnoreExifOrientation, ColorManagementMode.ColorManageToSRgb);
var data = dataProvider.DetachPixelData();
int width = (int)decoder.PixelWidth;
int height = (int)decoder.PixelHeight;
Mipmaps = new Mipmap[1];
Size = new Size2(width, height);
Mipmaps[0] = new Mipmap(data, width, height, 1, 4);
if (flip) Mipmaps[0].FlipVertical();
}
}
catch (Exception e)
{
FailedToLoad = true;
Loader.AddLoadableException(e);
if (loadedCallback != null) loadedCallback(this, false);
return;
}
Loaded = true;
if (loadedCallback != null) loadedCallback(this, true);
}
public static async Task<string> SaveStreamAsync(IRandomAccessStream streamToSave, uint width, uint height, string fileName)
{
FolderPicker folderPicker = new FolderPicker();
folderPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
folderPicker.ViewMode = PickerViewMode.List;
folderPicker.FileTypeFilter.Add(".jpg");
folderPicker.FileTypeFilter.Add(".jpeg");
folderPicker.FileTypeFilter.Add(".png");
StorageFolder newFolder = await folderPicker.PickSingleFolderAsync();
StorageFile destination = await newFolder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
BitmapTransform transform = new BitmapTransform();
BitmapDecoder bmpDecoder = await BitmapDecoder.CreateAsync(streamToSave);
PixelDataProvider pixelData = await bmpDecoder.GetPixelDataAsync(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.DoNotColorManage);
using (var destFileStream = await destination.OpenAsync(FileAccessMode.ReadWrite))
{
BitmapEncoder bmpEncoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, destFileStream);
bmpEncoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, width, height, 300, 300, pixelData.DetachPixelData());
await bmpEncoder.FlushAsync();
}
return destination.Path;
}
public async Task<IBitmap> Load(Stream sourceStream, float? desiredWidth, float? desiredHeight)
{
using (var rwStream = new InMemoryRandomAccessStream()) {
await sourceStream.CopyToAsync(rwStream.AsStreamForWrite());
var decoder = await BitmapDecoder.CreateAsync(rwStream);
var transform = new BitmapTransform();
if (desiredWidth != null) {
transform.ScaledWidth = (uint)desiredWidth;
transform.ScaledHeight = (uint)desiredHeight;
}
var pixelData = await decoder.GetPixelDataAsync(decoder.BitmapPixelFormat, decoder.BitmapAlphaMode, transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.ColorManageToSRgb);
var pixels = pixelData.DetachPixelData();
WriteableBitmap bmp = new WriteableBitmap((int)decoder.OrientedPixelWidth, (int)decoder.OrientedPixelHeight);
using (var bmpStream = bmp.PixelBuffer.AsStream()) {
bmpStream.Seek(0, SeekOrigin.Begin);
bmpStream.Write(pixels, 0, (int)bmpStream.Length);
return (IBitmap) new WriteableBitmapImageBitmap(bmp);
}
}
}
private async void LoadImageUsingPixelBuffer_Click(object sender, RoutedEventArgs e)
{
// This method loads an image into the WriteableBitmap by decoding it into a byte stream
// and copying the result into the WriteableBitmap's pixel buffer
FileOpenPicker picker = new FileOpenPicker();
picker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
picker.FileTypeFilter.Add(".png");
picker.FileTypeFilter.Add(".jpeg");
picker.FileTypeFilter.Add(".jpg");
picker.FileTypeFilter.Add(".bmp");
StorageFile file = await picker.PickSingleFileAsync();
// Ensure a file was selected
if (file != null)
{
using (IRandomAccessStream fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read))
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(fileStream);
// Scale image to appropriate size
BitmapTransform transform = new BitmapTransform() {
ScaledWidth = Convert.ToUInt32(Scenario4WriteableBitmap.PixelWidth),
ScaledHeight = Convert.ToUInt32(Scenario4WriteableBitmap.PixelHeight)};
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8, // WriteableBitmap uses BGRA format
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.IgnoreExifOrientation, // This sample ignores Exif orientation
ColorManagementMode.DoNotColorManage);
// An array containing the decoded image data, which could be modified before being displayed
byte[] sourcePixels = pixelData.DetachPixelData();
// Open a stream to copy the image contents to the WriteableBitmap's pixel buffer
using (Stream stream = Scenario4WriteableBitmap.PixelBuffer.AsStream())
{
await stream.WriteAsync(sourcePixels, 0, sourcePixels.Length);
}
}
// Redraw the WriteableBitmap
Scenario4WriteableBitmap.Invalidate();
}
}
/// <summary>
/// 异步从网络下载图片
/// </summary>
/// <param name="outfileName">下载保存到本地的图片文件名</param>
/// <param name="downloadUriString">图片uri</param>
/// <param name="scaleSize">图片尺寸</param>
/// <returns></returns>
public static async Task DownloadAndScale(string outfileName, string downloadUriString, Size scaleSize)
{
try
{
Uri downLoadingUri = new Uri(downloadUriString);//创建uri对象
HttpClient client = new HttpClient();//实例化httpclient对象
using (var response = await client.GetAsync(downLoadingUri))
{
var buffer = await response.Content.ReadAsBufferAsync();//从返回的数据中读取buffer
var memoryStream = new InMemoryRandomAccessStream();
await memoryStream.WriteAsync(buffer);//将buffer写入memorystream
await memoryStream.FlushAsync();//刷新
var decoder = await Windows.Graphics.Imaging.BitmapDecoder.CreateAsync(memoryStream);//解密文件流
//确定图片大小
var bt = new Windows.Graphics.Imaging.BitmapTransform();
bt.ScaledWidth = (uint)scaleSize.Width;
bt.ScaledHeight = (uint)scaleSize.Height;
//得到像素数值
var pixelProvider = await decoder.GetPixelDataAsync(
decoder.BitmapPixelFormat, decoder.BitmapAlphaMode, bt,
ExifOrientationMode.IgnoreExifOrientation, ColorManagementMode.ColorManageToSRgb);
//下面保存图片
// Now that we have the pixel data, get the destination file
var localFolder = ApplicationData.Current.LocalFolder;
//var resultsFolder = await localFolder.CreateFolderAsync("Results", CreationCollisionOption.OpenIfExists);
var scaledFile = await localFolder.CreateFileAsync(outfileName, CreationCollisionOption.ReplaceExisting);
using (var scaledFileStream = await scaledFile.OpenAsync(FileAccessMode.ReadWrite))
{
var encoder = await BitmapEncoder.CreateAsync(
BitmapEncoder.JpegEncoderId, scaledFileStream);
var pixels = pixelProvider.DetachPixelData();
encoder.SetPixelData(
decoder.BitmapPixelFormat,
decoder.BitmapAlphaMode,
(uint)scaleSize.Width,
(uint)scaleSize.Height,
decoder.DpiX,
decoder.DpiY,
pixels
);
await encoder.FlushAsync();
}
}
}
catch (Exception) { Debug.WriteLine("工具，图片异常"); }
}
private async Task<IRandomAccessStream> ResizeJpegStreamAsync(int maxPixelDimension, int percentQuality, IRandomAccessStream input)
{
var decoder = await BitmapDecoder.CreateAsync(input);
int targetHeight;
int targetWidth;
MvxPictureDimensionHelper.TargetWidthAndHeight(maxPixelDimension, (int)decoder.PixelWidth, (int)decoder.PixelHeight, out targetWidth, out targetHeight);
var transform = new BitmapTransform() { ScaledHeight = (uint)targetHeight, ScaledWidth = (uint)targetWidth };
var pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.DoNotColorManage);
var destinationStream = new InMemoryRandomAccessStream();
var bitmapPropertiesSet = new BitmapPropertySet();
bitmapPropertiesSet.Add("ImageQuality", new BitmapTypedValue(((double)percentQuality) / 100.0, PropertyType.Single));
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, destinationStream, bitmapPropertiesSet);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Premultiplied, (uint)targetWidth, (uint)targetHeight, decoder.DpiX, decoder.DpiY, pixelData.DetachPixelData());
await encoder.FlushAsync();
destinationStream.Seek(0L);
return destinationStream;
}
private async void loadnew()
{
Assembly assembly = typeof(Clr_Pckr).GetTypeInfo().Assembly;
//Stream imgStream = assembly.GetManifestResourceStream("Color_Picker.Assets.c.png");
InMemoryRandomAccessStream res = new InMemoryRandomAccessStream();
using (var imgstream = assembly.GetManifestResourceStream("Dev.MartijnHoogendoorn.Inking.Behavior.Assets.c.png"))
{
await imgstream.CopyToAsync(res.AsStreamForWrite());
}
BitmapImage bmp = new BitmapImage();
using (IRandomAccessStream fileStream =res)// await( await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/c.png"))).OpenAsync(FileAccessMode.Read))
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(fileStream);
fileStream.Seek(0);
bmp.SetSource(fileStream);
ColorImg.Source = bmp;
BitmapTransform bt = new BitmapTransform();
bt.ScaledHeight = 100;
bt.ScaledWidth = 100;
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Straight,
bt,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.DoNotColorManage);
bd = decoder;
//byte[] sourcePixels = pixelData.DetachPixelData();
tempBuffer = pixelData.DetachPixelData();
}
}
async public void SaveAndCropCover(StorageFile originalImgFile)
{
using (IRandomAccessStream stream = await originalImgFile.OpenReadAsync())
{
// Create a decoder from the stream. With the decoder, we can get
// the properties of the image.
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream);
var shortSide = Math.Min(decoder.PixelWidth, decoder.PixelHeight);
double scale = Math.Min(1, shortSide / 480);
Size corpSize = new Size(shortSide, shortSide);
Point startPoint = new Point((decoder.PixelWidth - shortSide) / 2, (decoder.PixelHeight - shortSide) / 2);
// Source: https://code.msdn.microsoft.com/windowsapps/CSWin8AppCropBitmap-52fa1ad7
if (double.IsNaN(scale) || double.IsInfinity(scale))
{
scale = 1;
}
// Convert start point and size to integer.
uint startPointX = (uint)Math.Floor(startPoint.X * scale);
uint startPointY = (uint)Math.Floor(startPoint.Y * scale);
uint height = (uint)Math.Floor(corpSize.Height * scale);
uint width = (uint)Math.Floor(corpSize.Width * scale);
// The scaledSize of original image.
uint scaledWidth = (uint)Math.Floor(decoder.PixelWidth * scale);
uint scaledHeight = (uint)Math.Floor(decoder.PixelHeight * scale);
// Refine the start point and the size.
if (startPointX + width > scaledWidth)
{
startPointX = scaledWidth - width;
}
if (startPointY + height > scaledHeight)
{
startPointY = scaledHeight - height;
}
// Create cropping BitmapTransform and define the bounds.
BitmapTransform transform = new BitmapTransform();
BitmapBounds bounds = new BitmapBounds();
bounds.X = startPointX;
bounds.Y = startPointY;
bounds.Height = height;
bounds.Width = width;
transform.Bounds = bounds;
transform.ScaledWidth = scaledWidth;
transform.ScaledHeight = scaledHeight;
// Get the cropped pixels within the bounds of transform.
PixelDataProvider pix = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.ColorManageToSRgb);
byte[] pixels = pix.DetachPixelData();
// Stream the bytes into a WriteableBitmap
WriteableBitmap cropBmp = new WriteableBitmap((int)width, (int)height);
Stream pixStream = cropBmp.PixelBuffer.AsStream();
pixStream.Write(pixels, 0, (int)(width * height * 4));
this.SaveCover(cropBmp);
}
}
/// <summary>
/// Scales an image down. Not a very good algo, but good enough.
/// </summary>
/// <param name="filename"></param>
/// <returns></returns>
public async Task<bool> scaleImage(string filename)
{
var applicationData = Windows.Storage.ApplicationData.Current;
methodLibrary mlb = new methodLibrary();
Image image = new Image();
int height = 0;
int scaledHeight = 80 ;
int scaledWidth = 80;
int width = 0;
var localFolder = applicationData.LocalFolder;
try
{
StorageFile sourceFile= await localFolder.GetFileAsync(filename + ".png");
IRandomAccessStreamWithContentType stream = await sourceFile.OpenReadAsync();
ImageProperties properties = await sourceFile.Properties.GetImagePropertiesAsync();
height = (int)properties.Height;
width = (int)properties.Width;
double scaleBy = 0;
for (int scale = 10; scale > 0; scale--)
{
if (((height * scale *0.1) <= 80) || ((width * scale *0.1) <= 80))
{
scaleBy = scale + 1;
break;
}
}
if (height != 0)
{
scaledHeight = (int)(height * scaleBy * 0.1);
}
if (width != 0)
{
scaledWidth = (int)(width * scaleBy * 0.1);
}
if(scaleBy == 0)
{
scaledHeight = (int)(height * 0.1);
scaledWidth = (int)(width * 0.1);
}
StorageFile destinationFile = await localFolder.CreateFileAsync(filename + "_scaled.png", CreationCollisionOption.ReplaceExisting);
using (var sourceStream = await sourceFile.OpenAsync(FileAccessMode.Read))
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(sourceStream);
BitmapTransform transform = new BitmapTransform() { ScaledHeight = (uint)scaledHeight, ScaledWidth = (uint)scaledWidth };
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.DoNotColorManage);
Debug.WriteLine("Actual height : " + height + " Scaled height : " + scaledHeight);
Debug.WriteLine("Actual width : " + width+ " Scaled width : " + scaledWidth);
using (var destinationStream = await destinationFile.OpenAsync(FileAccessMode.ReadWrite))
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, destinationStream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Premultiplied, (uint)scaledWidth, (uint)scaledHeight, 96, 96, pixelData.DetachPixelData());
await encoder.FlushAsync();
}
}
}
catch (Exception ex)
{
Debug.WriteLine("Exception in scaling image assets : " + ex);
await mlb.writeToLogFile(DateTime.UtcNow.ToString() + "Exception in scaling image assets", false);
return false;
}
return true;
}
/// <summary>
/// Applies the user-provided scale and rotation operation to a new image file picked by the user.
/// This method writes the edited pixel data to the new file without
/// any regard to existing metadata or other information in the original file.
/// </summary>
private async void SaveAs_Click(object sender, RoutedEventArgs e)
{
try
{
rootPage.NotifyUser("Saving to a new file...", NotifyType.StatusMessage);
StorageFile inputFile = await m_futureAccess.GetFileAsync(m_fileToken);
StorageFile outputFile = await Helpers.GetFileFromSavePickerAsync();
Guid encoderId;
switch (outputFile.FileType)
{
case ".png":
encoderId = BitmapEncoder.PngEncoderId;
break;
case ".bmp":
encoderId = BitmapEncoder.BmpEncoderId;
break;
case ".jpg":
default:
encoderId = BitmapEncoder.JpegEncoderId;
break;
}
using (IRandomAccessStream inputStream = await inputFile.OpenAsync(FileAccessMode.Read),
outputStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
// BitmapEncoder expects an empty output stream; the user may have selected a
// pre-existing file.
outputStream.Size = 0;
// Get pixel data from the decoder. We apply the user-requested transforms on the
// decoded pixels to take advantage of potential optimizations in the decoder.
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(inputStream);
BitmapTransform transform = new BitmapTransform();
// Scaling occurs before flip/rotation, therefore use the original dimensions
// (no orientation applied) as parameters for scaling.
transform.ScaledHeight = (uint)(decoder.PixelHeight * m_scaleFactor);
transform.ScaledWidth = (uint)(decoder.PixelWidth * m_scaleFactor);
transform.Rotation = Helpers.ConvertToBitmapRotation(m_userRotation);
// Fant is a relatively high quality interpolation mode.
transform.InterpolationMode = BitmapInterpolationMode.Fant;
// The BitmapDecoder indicates what pixel format and alpha mode best match the
// natively stored image data. This can provide a performance and/or quality gain.
BitmapPixelFormat format = decoder.BitmapPixelFormat;
BitmapAlphaMode alpha = decoder.BitmapAlphaMode;
PixelDataProvider pixelProvider = await decoder.GetPixelDataAsync(
format,
alpha,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.ColorManageToSRgb
);
byte[] pixels = pixelProvider.DetachPixelData();
// Write the pixel data onto the encoder. Note that we can't simply use the
// BitmapTransform.ScaledWidth and ScaledHeight members as the user may have
// requested a rotation (which is applied after scaling).
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(encoderId, outputStream);
encoder.SetPixelData(
format,
alpha,
(uint)((double)m_displayWidthNonScaled * m_scaleFactor),
(uint)((double)m_displayHeightNonScaled * m_scaleFactor),
decoder.DpiX,
decoder.DpiY,
pixels
);
await encoder.FlushAsync();
rootPage.NotifyUser("Successfully saved a copy: " + outputFile.Name, NotifyType.StatusMessage);
}
}
catch (Exception err)
{
rootPage.NotifyUser("Error: " + err.Message, NotifyType.ErrorMessage);
ResetPersistedState();
ResetSessionState();
}
}
/// <summary>
/// Resizes the specified stream.
/// </summary>
/// <param name="sourceStream">The source stream to resize.</param>
/// <param name="newWidth">The width of the resized image.</param>
/// <param name="newHeight">The height of the resized image.</param>
/// <returns>The resized image stream.</returns>
public static async Task<InMemoryRandomAccessStream> Resize(IRandomAccessStream sourceStream, uint newWidth,
uint newHeight)
{
var destinationStream = new InMemoryRandomAccessStream();
var decoder = await BitmapDecoder.CreateAsync(sourceStream);
var transform = new BitmapTransform { ScaledWidth = newWidth, ScaledHeight = newHeight };
var pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.DoNotColorManage);
var encoder =
await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, destinationStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied, newWidth, newHeight, 96, 96,
pixelData.DetachPixelData());
await encoder.FlushAsync();
return destinationStream;
}
/// <summary>
/// rotates the image by the currentRotation value
/// </summary>
/// <param name="mrs">InMemoryRandomAccessStream containg the image data</param>
/// <returns>byte [] to be sent through processing</returns>
async private Task<byte[]> RotateImage(InMemoryRandomAccessStream mrs)
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(mrs).AsTask().ConfigureAwait(false);
uint w = decoder.PixelWidth; uint h = decoder.PixelHeight;
if (currentRotation.Equals(VideoRotation.Clockwise90Degrees) || currentRotation.Equals(VideoRotation.Clockwise270Degrees))
{
w = decoder.PixelHeight;
h = decoder.PixelWidth;
}
BitmapTransform transform = new BitmapTransform() { Rotation = (BitmapRotation)currentRotation };
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Premultiplied,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.DoNotColorManage);
byte[] pixels = pixelData.DetachPixelData();
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, mrs);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Premultiplied, w, h, 96, 96, pixels);
await encoder.FlushAsync().AsTask().ConfigureAwait(false);
mrs.Seek(0);
byte[] outBytes = new byte[mrs.Size];
await mrs.AsStream().ReadAsync(outBytes, 0, outBytes.Length);
MemoryStream ms = new MemoryStream(outBytes);
var currentApp = (App)App.Current;
currentApp.CurrentImageRecog = ms;
return outBytes;
}
/// <summary>
/// 改变图片的大小
/// </summary>
/// <param name="sourceStream">包含图片数据的流</param>
/// <param name="expWidth">期望的宽度</param>
/// <param name="expHeight">期望的高度</param>
/// <returns></returns>
public static async Task<IRandomAccessStream> ResizeImageHard(IRandomAccessStream sourceStream, uint expWidth,uint expHeight)
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(sourceStream);
uint height = decoder.PixelHeight;
uint weight = decoder.PixelWidth;
uint destHeight = height > expHeight ? expHeight : height;
uint destWeight = weight> expWidth? expWidth : weight;
BitmapTransform transform = new BitmapTransform()
{
ScaledWidth = destWeight,
ScaledHeight = destHeight
};
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Rgba8,
BitmapAlphaMode.Straight,
transform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.DoNotColorManage);
var tempfile = await ApplicationData.Current.LocalFolder.CreateFileAsync("temp.jpg", CreationCollisionOption.ReplaceExisting);
IRandomAccessStream destStream = await tempfile.OpenAsync(FileAccessMode.ReadWrite);
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, destStream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, transform.ScaledWidth, transform.ScaledHeight, 100, 100, pixelData.DetachPixelData());
await encoder.FlushAsync();
//把流的位置变为0，这样才能从头读出图片流
destStream.Seek(0);
return destStream;
}
private static async Task<WriteableBitmap> FromContentWinRt(this WriteableBitmap bmp, Uri uri)
{
if (bmp == null) throw new ArgumentNullException("bmp");
// Decode pixel data
var file = await StorageFile.GetFileFromApplicationUriAsync(uri);
var decoder = await BitmapDecoder.CreateAsync(await file.OpenAsync(FileAccessMode.Read));
var transform = new BitmapTransform();
var pixelData = await decoder.GetPixelDataAsync(decoder.BitmapPixelFormat, decoder.BitmapAlphaMode, transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.ColorManageToSRgb);
// Swap R and B channels
var pixels = pixelData.DetachPixelData();
for (var i = 0; i < pixels.Length; i += 4)
{
var r = pixels[i];
var b = pixels[i + 2];
pixels[i] = b;
pixels[i + 2] = r;
}
// Copy to WriteableBitmap
bmp = new WriteableBitmap((int)decoder.PixelWidth, (int)decoder.PixelHeight);
using (var bmpStream = bmp.PixelBuffer.AsStream())
{
bmpStream.Seek(0, SeekOrigin.Begin);
bmpStream.Write(pixels, 0, (int)bmpStream.Length);
return bmp;
}
}
private async Task<byte[]> GetImageAsByteAsync(Guid format, int quality, int desiredWidth, int desiredHeight)
{
if (internalImage == null || internalImage.Source == null)
return null;
var bitmap = internalImage.Source as WriteableBitmap;
if (bitmap == null)
return null;
byte[] pixels = null;
uint pixelsWidth = (uint)bitmap.PixelWidth;
uint pixelsHeight = (uint)bitmap.PixelHeight;
if (desiredWidth != 0 || desiredHeight != 0)
{
double widthRatio = (double)desiredWidth / (double)bitmap.PixelWidth;
double heightRatio = (double)desiredHeight / (double)bitmap.PixelHeight;
double scaleRatio = Math.Min(widthRatio, heightRatio);
if (desiredWidth == 0)
scaleRatio = heightRatio;
if (desiredHeight == 0)
scaleRatio = widthRatio;
uint aspectWidth = (uint)((double)bitmap.PixelWidth * scaleRatio);
uint aspectHeight = (uint)((double)bitmap.PixelHeight * scaleRatio);
using (var tempStream = new InMemoryRandomAccessStream())
{
byte[] tempPixels = await GetBytesFromBitmapAsync(bitmap);
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, tempStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied,
pixelsWidth, pixelsHeight, 96, 96, tempPixels);
await encoder.FlushAsync();
tempStream.Seek(0);
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(tempStream);
BitmapTransform transform = new BitmapTransform()
{
ScaledWidth = aspectWidth,
ScaledHeight = aspectHeight,
InterpolationMode = BitmapInterpolationMode.Linear
};
PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Premultiplied,
transform,
ExifOrientationMode.RespectExifOrientation,
ColorManagementMode.DoNotColorManage);
pixels = pixelData.DetachPixelData();
pixelsWidth = aspectWidth;
pixelsHeight = aspectHeight;
}
}
else
{
pixels = await GetBytesFromBitmapAsync(bitmap);
}
using (var stream = new InMemoryRandomAccessStream())
{
var encoder = await BitmapEncoder.CreateAsync(format, stream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied,
pixelsWidth, pixelsHeight, 96, 96, pixels);
await encoder.FlushAsync();
stream.Seek(0);
var bytes = new byte[stream.Size];
await stream.ReadAsync(bytes.AsBuffer(), (uint)stream.Size, InputStreamOptions.None);
return bytes;
}
}
