/// <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;
}
internal static async Task LoadTileImageInternalAsync(string imagePath)
{
string tileName = "dreaming";
uint MaxImageWidth =360;
uint MaxImageHeight = 600;
StorageFile origFile = await ApplicationData.Current.LocalFolder.GetFileAsync(imagePath);
// open file for the new tile image file
StorageFile tileFile = await Windows.Storage.KnownFolders.PicturesLibrary.CreateFileAsync(tileName, CreationCollisionOption.GenerateUniqueName);
using (IRandomAccessStream tileStream = await tileFile.OpenAsync(FileAccessMode.ReadWrite))
{
// get width and height from the original image
IRandomAccessStreamWithContentType stream = await origFile.OpenReadAsync();
ImageProperties properties = await origFile.Properties.GetImagePropertiesAsync();
uint width = properties.Width;
uint height = properties.Height;
// get proper decoder for the input file - jpg/png/gif
BitmapDecoder decoder = await GetProperDecoder(stream, origFile );
if (decoder == null) return; // should not happen
// get byte array of actual decoded image
PixelDataProvider data = await decoder.GetPixelDataAsync();
byte[] bytes = data.DetachPixelData();
// create encoder for saving the tile image
BitmapPropertySet propertySet = new BitmapPropertySet();
// create class representing target jpeg quality - a bit obscure, but it works
BitmapTypedValue qualityValue = new BitmapTypedValue(0.5, PropertyType.Single);
propertySet.Add("ImageQuality", qualityValue);
// create the target jpeg decoder
BitmapEncoder be = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, tileStream, propertySet);
be.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, width, height, 96.0, 96.0, bytes);
// crop the image, if it's too big
if (width > MaxImageWidth || height > MaxImageHeight)
{
BitmapBounds bounds = new BitmapBounds();
if (width > MaxImageWidth)
{
bounds.Width = MaxImageWidth;
bounds.X = (width - MaxImageWidth) / 2;
}
else bounds.Width = width;
if (height > MaxImageHeight)
{
bounds.Height = MaxImageHeight;
bounds.Y = (height - MaxImageHeight) / 2;
}
else bounds.Height = height;
be.BitmapTransform.Bounds = bounds;
}
// save the target jpg to the file
await be.FlushAsync();
}
}
public static async Task<byte[]> CropImage(byte[] stream, Crop crop)
{
byte[] byteArray = null;
var imageStream = new MemoryStream(stream);
var fileStream = imageStream.AsRandomAccessStream();
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(fileStream);
InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream();
BitmapEncoder enc = await BitmapEncoder.CreateForTranscodingAsync(ras, decoder);
BitmapBounds bounds = new BitmapBounds();
bounds.Height = (uint)crop.Height;
bounds.Width = (uint)crop.Width;
bounds.X = (uint)crop.X;
bounds.Y = (uint)crop.Y;
enc.BitmapTransform.Bounds = bounds;
enc.BitmapTransform.InterpolationMode = BitmapInterpolationMode.Linear;
enc.IsThumbnailGenerated = false;
try
{
await enc.FlushAsync();
}
catch (Exception ex)
{
Debug.WriteLine("Error croping image", ex);
}
byteArray = new byte[ras.Size];
DataReader dataReader = new DataReader(ras.GetInputStreamAt(0));
await dataReader.LoadAsync((uint)ras.Size);
dataReader.ReadBytes(byteArray);
return byteArray;
}
/// <summary>
/// Helper to get the correct Bounds for 15:9 screens and to set finalPhotoAreaBorder values
/// </summary>
/// <returns></returns>
private BitmapBounds GetFifteenByNineBounds()
{
var bounds = new BitmapBounds();
//image size is raw pixels, so we need also here raw pixels
var logicalPixelWidth = Window.Current.Bounds.Width;
var logicalPixelHeight = Window.Current.Bounds.Height;
var rawPerViewPixels = DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;
var rawPixelHeight = logicalPixelHeight*rawPerViewPixels;
var rawPixelWidth = logicalPixelWidth*rawPerViewPixels;
//calculate scale factor of UniformToFill Height (remember, we rotated the preview)
var scaleFactorVisualHeight = maxResolution().Width/rawPixelHeight;
//calculate the visual Width
//(because UniFormToFill scaled the previewElement Width down to match the previewElement Height)
var visualWidth = maxResolution().Height/scaleFactorVisualHeight;
//calculate cropping area for 15:9
var scaledBoundsWidth = maxResolution().Height;
var scaledBoundsHeight = (scaledBoundsWidth/9)*15;
//we are starting at the top of the image
bounds.Y = 0;
//cropping the image width
bounds.X = 0;
bounds.Height = scaledBoundsHeight;
bounds.Width = scaledBoundsWidth;
//set finalPhotoAreaBorder values that shows the user the area that is captured
//finalPhotoAreaBorder.Width = (scaledBoundsWidth / scaleFactorVisualHeight) / rawPerViewPixels;
//finalPhotoAreaBorder.Height = (scaledBoundsHeight / scaleFactorVisualHeight) / rawPerViewPixels;
//finalPhotoAreaBorder.Margin = new Thickness(
// Math.Floor(((rawPixelWidth - visualWidth) / 2) / rawPerViewPixels),
// 0,
// Math.Floor(((rawPixelWidth - visualWidth) / 2) / rawPerViewPixels),
// 0);
//finalPhotoAreaBorder.Visibility = Visibility.Visible;
return bounds;
}
private static async Task<StorageFile> GenerateResizedImageAsync(StorageFile inputFile, uint width, uint height, uint edgePadding = 5, uint bottomPadding = 20, NameCollisionOption collisionOption = NameCollisionOption.ReplaceExisting)
{
try
{
string fileName = inputFile.DisplayName + width + "x" + height;
string extension = inputFile.Name.Substring(inputFile.Name.LastIndexOf('.'));
string folder = inputFile.Path.Substring(0, inputFile.Path.LastIndexOf('\\'));
var outputFolder = await StorageFolder.GetFolderFromPathAsync(folder);
var newFile = await outputFolder.CreateFileAsync(fileName + extension, CreationCollisionOption.ReplaceExisting);
var inputStream = await inputFile.OpenAsync(Windows.Storage.FileAccessMode.Read);
var outputStream = await newFile.OpenTransactedWriteAsync();
var inMemStream = new InMemoryRandomAccessStream();
var decoder = await BitmapDecoder.CreateAsync(inputStream);
var encoder = await BitmapEncoder.CreateForTranscodingAsync(inMemStream, decoder);
// Find aspect ratio for resize
float nPercentW = (((float)width - (edgePadding * 2)) / (float)decoder.PixelWidth);
float nPercentH = (((float)height - (edgePadding * 2)) / (float)decoder.PixelHeight);
float nPercent = nPercentH < nPercentW ? nPercentH : nPercentW;
// Scale height and width
if (nPercent < 1)
{
encoder.BitmapTransform.ScaledHeight = (uint)(decoder.PixelHeight * nPercent);
encoder.BitmapTransform.ScaledWidth = (uint)(decoder.PixelWidth * nPercent);
}
// Image may still exceed intended bounds, resize as appropriate
if (encoder.BitmapTransform.ScaledWidth > width || encoder.BitmapTransform.ScaledHeight > height)
{
BitmapBounds bounds = new BitmapBounds();
if (encoder.BitmapTransform.ScaledWidth > width)
{
bounds.Width = width;
bounds.X = (encoder.BitmapTransform.ScaledWidth - width) / 2;
}
else
bounds.Width = encoder.BitmapTransform.ScaledWidth;
if (encoder.BitmapTransform.ScaledHeight > height)
{
bounds.Height = height;
bounds.Y = (encoder.BitmapTransform.ScaledHeight - height) / 2;
}
else
bounds.Height = encoder.BitmapTransform.ScaledHeight;
encoder.BitmapTransform.Bounds = bounds;
}
await encoder.FlushAsync();
var outDecoder = await BitmapDecoder.CreateAsync(inMemStream);
var outEncoder = await BitmapEncoder.CreateForTranscodingAsync(outputStream.Stream, outDecoder);
var transparentBytes = GenerateTransparentBitmap(width, height);
PixelDataProvider data = await outDecoder.GetPixelDataAsync();
uint heightOffset = (height - outDecoder.PixelHeight) / 2 - bottomPadding;
uint widthOffset = (width - outDecoder.PixelWidth) / 2;
byte[] bytes = MergePixelArrays(transparentBytes, width, height, data.DetachPixelData(), outDecoder.PixelWidth, outDecoder.PixelHeight, widthOffset, heightOffset);
outEncoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Straight, width, height, 72.0, 72.0, bytes);
await outEncoder.FlushAsync();
return newFile;
}
catch (Exception)
{
}
return null;
}
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);
}
}
private async void BitmapTransform(string filePath)
{
var client = new HttpClient();
var stream = await client.GetStreamAsync(filePath);
var memStream = new MemoryStream();
await stream.CopyToAsync(memStream);
memStream.Position = 0;
var decoder = await BitmapDecoder.CreateAsync(memStream.AsRandomAccessStream());
var ras = new InMemoryRandomAccessStream();
var enc = await BitmapEncoder.CreateForTranscodingAsync(ras, decoder);
var frame = await decoder.GetFrameAsync(0);
enc.BitmapTransform.ScaledHeight = frame.PixelHeight;
enc.BitmapTransform.ScaledWidth = frame.PixelWidth;
var bounds = new BitmapBounds
{
Height = 80,
Width = frame.PixelWidth,
X = 0,
Y = 0
};
enc.BitmapTransform.Bounds = bounds;
try
{
await enc.FlushAsync();
}
catch (Exception ex)
{
Debug.WriteLine(ex.ToString());
}
var bImg = BitmapFactory.New((int) frame.PixelWidth, (int) frame.PixelHeight);
using (bImg.GetBitmapContext())
{
bImg = await BitmapFactory.New((int) frame.PixelWidth, (int) frame.PixelHeight).FromStream(ras);
bImg.ForEach(
(x, y, color) => color.ToString().Equals("#FFCECECE")
? Color.FromArgb(80, 0, 0, 0)
: Colors.WhiteSmoke);
}
BorderBrushStreamPlayer.ImageSource = bImg;
}
//public static async Task<bool> GenerateImageAsync(InMemoryRandomAccessStream ms, string newImageName)
//{
// using (var a = ms.AsStream())
// {
// byte[] b = new byte[a.Length];
// await a.ReadAsync(b, 0, (int)a.Length);
// StorageFile sampleFile = await _originalFolder.CreateFileAsync(newImageName);
// await FileIO.WriteBytesAsync(sampleFile, b);
// }
// return true;
//}
//public async Task<bool> GenerateResizedImageAsyncOld(int longWidth, double srcWidth, double srcHeight, InMemoryRandomAccessStream srcMemoryStream, string newImageName, location subFolder, int longHeight = 0)
//{
// if (_localFolder == null) InitFolders();
// try
// {
// int width = 0, height = 0;
// double factor = srcWidth / srcHeight;
// if (factor < 1)
// {
// height = longWidth;
// width = (int)(longWidth * factor);
// }
// else
// {
// width = longWidth;
// height = (int)(longWidth / factor);
// }
// if (longHeight > 0)
// {
// width = longWidth;
// height = longHeight;
// }
// WriteableBitmap wb = await BitmapFactory.New((int)srcWidth, (int)srcHeight).FromStream(srcMemoryStream);
// //WRITEABLE BITMAP IS THROWING AN ERROR
// var wbthumbnail = wb.Resize(width, height, Windows.UI.Xaml.Media.Imaging.WriteableBitmapExtensions.Interpolation.Bilinear);
// switch (subFolder)
// {
// case location.MediumFolder:
// StorageFile sampleFile1 = await _mediumFolder.CreateFileAsync(newImageName, CreationCollisionOption.ReplaceExisting);
// await wbthumbnail.SaveToFile(sampleFile1, BitmapEncoder.PngEncoderId);
// break;
// case location.ThumbFolder:
// StorageFile sampleFile2 = await _thumbFolder.CreateFileAsync(newImageName, CreationCollisionOption.ReplaceExisting);
// await wbthumbnail.SaveToFile(sampleFile2, BitmapEncoder.PngEncoderId);
// break;
// case location.TileFolder:
// StorageFile sampleFile3 = await _tileFolder.CreateFileAsync(newImageName, CreationCollisionOption.ReplaceExisting);
// await wbthumbnail.SaveToFile(sampleFile3, BitmapEncoder.PngEncoderId);
// break;
// }
// return true;
// }
// catch (Exception ex)
// {
// return false;
// }
//}
public async Task<bool> GenerateResizedImageAsync(int longWidth, double srcWidth, double srcHeight, InMemoryRandomAccessStream srcMemoryStream, string newImageName, location subFolder, int longHeight = 0)
{
if (_localFolder == null) InitFolders();
if (srcMemoryStream.Size == 0) return false;
try
{
int width = 0, height = 0;
double factor = srcWidth / srcHeight;
if (factor < 1)
{
height = longWidth;
width = (int)(longWidth * factor);
}
else
{
width = longWidth;
height = (int)(longWidth / factor);
}
if (longHeight > 0)
{
width = longWidth;
height = longHeight;
}
if (subFolder == location.MediumFolder) {
WriteableBitmap wb = await BitmapFactory.New((int)srcWidth, (int)srcHeight).FromStream(srcMemoryStream);
var wbthumbnail = wb.Resize(width, height, Windows.UI.Xaml.Media.Imaging.WriteableBitmapExtensions.Interpolation.Bilinear);
StorageFile sampleFile1 = await _mediumFolder.CreateFileAsync(newImageName, CreationCollisionOption.ReplaceExisting);
await wbthumbnail.SaveToFile(sampleFile1, BitmapEncoder.PngEncoderId);
}
else if (subFolder == location.ThumbFolder)
{
WriteableBitmap wb = await BitmapFactory.New((int)srcWidth, (int)srcHeight).FromStream(srcMemoryStream);
var wbthumbnail = wb.Resize(width, height, Windows.UI.Xaml.Media.Imaging.WriteableBitmapExtensions.Interpolation.Bilinear);
StorageFile sampleFile2 = await _thumbFolder.CreateFileAsync(newImageName, CreationCollisionOption.ReplaceExisting);
await wbthumbnail.SaveToFile(sampleFile2, BitmapEncoder.PngEncoderId);
}
else if (subFolder == location.TileFolder) {
//https://social.msdn.microsoft.com/Forums/en-US/490b9c01-db4b-434f-8aff-d5c495e67e55/how-to-crop-an-image-using-bitmaptransform?forum=winappswithcsharp
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(srcMemoryStream);
using (InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream()) {
BitmapEncoder enc = await BitmapEncoder.CreateForTranscodingAsync(ras, decoder);
var h = longHeight / srcHeight;
var w = longWidth / srcWidth;
var r = Math.Max(h, w);
enc.BitmapTransform.ScaledWidth = (uint)(srcWidth * r);
enc.BitmapTransform.ScaledHeight = (uint)(srcHeight * r);
BitmapBounds bounds = new BitmapBounds();
bounds.Width = (uint)longWidth;
bounds.Height = (uint)longHeight;
bounds.X = 0;
bounds.Y = 0;
enc.BitmapTransform.Bounds = bounds;
await enc.FlushAsync();
WriteableBitmap wb = await BitmapFactory.New(longWidth, longHeight).FromStream(ras);
StorageFile sampleFile3 = await _tileFolder.CreateFileAsync(newImageName, CreationCollisionOption.ReplaceExisting);
await wb.SaveToFile(sampleFile3, BitmapEncoder.PngEncoderId);
}
}
return true;
}
catch //(Exception ex)
{
return false;
}
}
private Rectangle ConvertPreviewToUiRectangle(BitmapBounds faceBoxInPreviewCoordinates)
{
var result = new Rectangle();
var previewStream = mediaCapture.VideoDeviceController.GetMediaStreamProperties(MediaStreamType.VideoPreview) as VideoEncodingProperties;
// If there is no available information about the preview, return an empty rectangle, as re-scaling to the screen coordinates will be impossible
if (previewStream == null)
return result;
// Similarly, if any of the dimensions is zero (which would only happen in an error case) return an empty rectangle
if (previewStream.Width == 0 || previewStream.Height == 0)
return result;
double streamWidth = previewStream.Width;
double streamHeight = previewStream.Height;
// Get the rectangle that is occupied by the actual video feed
var previewInUI = GetPreviewStreamRectInControl(previewStream, PreviewControl);
// Scale the width and height from preview stream coordinates to window coordinates
result.Width = (faceBoxInPreviewCoordinates.Width / streamWidth) * previewInUI.Width;
result.Height = (faceBoxInPreviewCoordinates.Height / streamHeight) * previewInUI.Height;
// Scale the X and Y coordinates from preview stream coordinates to window coordinates
var x = (faceBoxInPreviewCoordinates.X / streamWidth) * previewInUI.Width;
var y = (faceBoxInPreviewCoordinates.Y / streamHeight) * previewInUI.Height;
Canvas.SetLeft(result, x);
Canvas.SetTop(result, y);
return result;
}
async void cropImage(IRandomAccessStream inputStream, uint bw, uint bh, uint w, uint h, string fname, StorageFolder folder)
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(inputStream);
InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream();
BitmapEncoder enc = await BitmapEncoder.CreateForTranscodingAsync(ras, decoder);
BitmapBounds bounds = new BitmapBounds();
bounds.Height = h;
bounds.Width = w;
bounds.X = bw;
bounds.Y = bh;
enc.BitmapTransform.Bounds = bounds;
// write out to the stream
try
{
await enc.FlushAsync();
}
catch (Exception ex)
{
string s = ex.ToString();
}
ras.Seek(0);
// render the stream to the screen
BitmapImage bImg = new BitmapImage();
bImg.SetSource(ras);
imgHidden.Source = bImg; // image element in xaml
if (folder != null)
{
StorageFile file1 = await folder.CreateFileAsync(fname + "."+imgFormat, CreationCollisionOption.ReplaceExisting);
using (var fileStream1 = await file1.OpenAsync(FileAccessMode.ReadWrite))
{
await RandomAccessStream.CopyAndCloseAsync(ras.GetInputStreamAt(0), fileStream1.GetOutputStreamAt(0));
}
}
}
private async Task<InMemoryRandomAccessStream> ResizeImage(InMemoryRandomAccessStream stream, Size requiredSize)
{
// Make a decoder for the current stream
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream);
uint imageHeight = decoder.PixelHeight;
uint imageWidth = decoder.PixelWidth;
double widthRatio = imageWidth / requiredSize.Width;
double heightRatio = imageHeight / requiredSize.Height;
uint outputHeight = imageHeight;
uint outputWidth = imageWidth;
bool centerOnX = false;
if (widthRatio < heightRatio)
{
outputHeight = (uint)(imageHeight / widthRatio);
outputWidth = (uint)requiredSize.Width;
centerOnX = false;
}
else
{
outputWidth = (uint)(imageWidth / heightRatio);
outputHeight = (uint)requiredSize.Height;
centerOnX = true;
}
// Make an output stream and an encoder
InMemoryRandomAccessStream outputStream = new InMemoryRandomAccessStream();
BitmapEncoder enc = await BitmapEncoder.CreateForTranscodingAsync(outputStream, decoder);
// convert the entire bitmap to a 125px by 125px bitmap
enc.BitmapTransform.ScaledHeight = outputHeight;
enc.BitmapTransform.ScaledWidth = outputWidth;
BitmapBounds bound = new BitmapBounds();
bound.Height = (uint)requiredSize.Height;
bound.Width = (uint)requiredSize.Width;
// Choose Fant for quality over perf.
enc.BitmapTransform.InterpolationMode = BitmapInterpolationMode.Fant;
if(centerOnX)
{
int width = ((int)outputWidth / 2) - ((int)bound.Width / 2);
bound.X = (uint)(width > 0 ? width : 0);
}
else
{
int height = ((int)outputHeight / 2) - ((int)bound.Height / 2);
bound.Y = (uint)(height > 0 ? height : 0);
}
enc.BitmapTransform.Bounds = bound;
// Do it
await enc.FlushAsync();
// Return the new stream
return outputStream;
}
/// <summary>
/// Helper to get the correct Bounds for 15:9 screens and to set finalPhotoAreaBorder values
/// </summary>
/// <returns></returns>
private BitmapBounds GetFifteenByNineBounds()
{
var bounds = new BitmapBounds();
// image size is raw pixels, so we need also here raw pixels
var logicalPixelWidth = Window.Current.Bounds.Width;
var logicalPixelHeight = Window.Current.Bounds.Height;
var rawPerViewPixels = DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;
var rawPixelHeight = logicalPixelHeight * rawPerViewPixels;
var rawPixelWidth = logicalPixelWidth * rawPerViewPixels;
// calculate scale factor of UniformToFill Height (remember, we rotated the preview)
var scaleFactorVisualHeight = this.maxResolution().Width / rawPixelHeight;
// calculate the visual Width
// (because UniFormToFill scaled the previewElement Width down to match the previewElement Height)
var visualWidth = this.maxResolution().Height / scaleFactorVisualHeight;
// calculate cropping area for 15:9
var scaledBoundsWidth = this.maxResolution().Height;
var scaledBoundsHeight = (scaledBoundsWidth / 9) * 15;
// we are starting at the top of the image
bounds.Y = 0;
// cropping the image width
bounds.X = 0;
bounds.Height = scaledBoundsHeight;
bounds.Width = scaledBoundsWidth;
return bounds;
}
private async Task<InMemoryRandomAccessStream> ResizeImage(InMemoryRandomAccessStream stream, Size requiredSize)
{
// Make a decoder for the current stream
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream);
uint imageHeight = decoder.PixelHeight;
uint imageWidth = decoder.PixelWidth;
double widthRatio = imageWidth / requiredSize.Width;
double heightRatio = imageHeight / requiredSize.Height;
uint outputHeight = imageHeight;
uint outputWidth = imageWidth;
if (widthRatio < heightRatio)
{
outputHeight = (uint)(imageHeight / widthRatio);
outputWidth = (uint)requiredSize.Width;
}
else
{
outputWidth = (uint)(imageWidth / heightRatio);
outputHeight = (uint)requiredSize.Height;
}
// Make an output stream and an encoder
InMemoryRandomAccessStream outputStream = new InMemoryRandomAccessStream();
BitmapEncoder enc = await BitmapEncoder.CreateForTranscodingAsync(outputStream, decoder);
// convert the entire bitmap to a 125px by 125px bitmap
enc.BitmapTransform.ScaledHeight = outputHeight;
enc.BitmapTransform.ScaledWidth = outputWidth;
BitmapBounds bound = new BitmapBounds();
bound.Height = (uint)requiredSize.Height;
bound.Width = (uint)requiredSize.Width;
enc.BitmapTransform.Bounds = bound;
// Do it
await enc.FlushAsync();
// Return the new stream
return outputStream;
}
public static async Task CropandScaleAsync(StorageFile source, StorageFile dest, Point startPoint, Size size, double m_scaleFactor)
{
uint startPointX = (uint)Math.Floor(startPoint.X);
uint startPointY = (uint)Math.Floor(startPoint.Y);
uint height = (uint)Math.Floor(size.Height);
uint width = (uint)Math.Floor(size.Width);
using (IRandomAccessStream sourceStream = await source.OpenReadAsync(),
destStream = await dest.OpenAsync(FileAccessMode.ReadWrite))
{
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(sourceStream);
var m_displayHeightNonScaled = decoder.OrientedPixelHeight;
var m_displayWidthNonScaled = decoder.OrientedPixelWidth;
// Use the native (no orientation applied) image dimensions because we want to handle
// orientation ourselves.
BitmapTransform transform = new BitmapTransform();
BitmapBounds bounds = new BitmapBounds();
bounds.X = (uint)(startPointX * m_scaleFactor);
bounds.Y = (uint)(startPointY * m_scaleFactor);
bounds.Height = (uint)(height * m_scaleFactor);
bounds.Width = (uint)(width * m_scaleFactor);
transform.Bounds = bounds;
// 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 = BitmapRotation.None;
// Fant is a relatively high quality interpolation mode.
transform.InterpolationMode = BitmapInterpolationMode.Fant;
BitmapPixelFormat format = decoder.BitmapPixelFormat;
BitmapAlphaMode alpha = decoder.BitmapAlphaMode;
// Set the encoder's destination to the temporary, in-memory stream.
PixelDataProvider pixelProvider = await decoder.GetPixelDataAsync(
format,
alpha,
transform,
ExifOrientationMode.IgnoreExifOrientation,
ColorManagementMode.ColorManageToSRgb
);
byte[] pixels = pixelProvider.DetachPixelData();
Guid encoderID = Guid.Empty;
switch (dest.FileType.ToLower())
{
case ".png":
encoderID = BitmapEncoder.PngEncoderId;
break;
case ".bmp":
encoderID = BitmapEncoder.BmpEncoderId;
break;
default:
encoderID = BitmapEncoder.JpegEncoderId;
break;
}
// 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).
var encoder = await BitmapEncoder.CreateAsync(encoderID, destStream);
encoder.SetPixelData(
format,
alpha,
(bounds.Width),
(bounds.Height),
decoder.DpiX,
decoder.DpiY,
pixels
);
await encoder.FlushAsync();
}
}
