Develop Reference

BitmapEncoder FlushAsync throws Argument Exception - c#

When I'm using below code for image processing it throws exception at FlushAsync(). Strangely this issue happens for some video files only. Can you help why this happen ?
private async Task<String> PreProcessVideoToGetTextAsync(StorageFile file, int i)
{ /*--------To get frame from video----------*/
var thumbnail = await GetThumbnailAsync(file, i);
BitmapImage bitmapImage = new BitmapImage();
StringBuilder ocr = null;
InMemoryRandomAccessStream randomAccessStream = new InMemoryRandomAccessStream();
await RandomAccessStream.CopyAsync(thumbnail, randomAccessStream);
randomAccessStream.Seek(0);
SoftwareBitmap inputBitmap;
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(randomAccessStream);
// create a new stream and encoder for the new image
InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream();
BitmapEncoder enc = await BitmapEncoder.CreateForTranscodingAsync(ras, decoder);
BitmapBounds bounds = new BitmapBounds();
bounds.Height = 270;//screnheight/4 =270
bounds.Width = 960;//screenwidth/2 =960
bounds.X = 960;//screenwidth/2 =960
bounds.Y = 810;
enc.BitmapTransform.Bounds = bounds;
// write out to the stream
try
{
await enc.FlushAsync();
}
catch (Exception ex)
{
string exx = ex.ToString();
var dialog = new MessageDialog(exx);
await dialog.ShowAsync();
}
//Remain portion of code
}

I've already used the following code snippet to save video thumbnails in my uwp app, hopefully you can apply a little bit of changes as you want to use it.
private async Task PreProcessVideoToGetTextAsync(string videopath)
{
try
{
SoftwareBitmap softwareBitmap = null;
StorageFile videofile = await StorageFile.GetFileFromPathAsync(videopath);
var thumbnail = await GetThumbnailAsync(videofile);
Windows.Storage.Streams.InMemoryRandomAccessStream randomAccessStream = new Windows.Storage.Streams.InMemoryRandomAccessStream();
await Windows.Storage.Streams.RandomAccessStream.CopyAsync(thumbnail, randomAccessStream);
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(randomAccessStream);
softwareBitmap = await decoder.GetSoftwareBitmapAsync();
StorageFile outputFile = await ApplicationData.Current.LocalCacheFolder.CreateFileAsync(Path.GetFileNameWithoutExtension(videopath) + ".jpg");//save path for video thumbnail image in app cache folder
using (Windows.Storage.Streams.IRandomAccessStream stream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, stream);
encoder.SetSoftwareBitmap(softwareBitmap);
encoder.BitmapTransform.ScaledWidth = 128;//thumbnail width
encoder.BitmapTransform.ScaledHeight = 128;//thumbnail height
encoder.IsThumbnailGenerated = true;
try
{
await encoder.FlushAsync();
if (softwareBitmap.BitmapPixelFormat != BitmapPixelFormat.Bgra8 || softwareBitmap.BitmapAlphaMode == BitmapAlphaMode.Straight)
{
softwareBitmap = SoftwareBitmap.Convert(softwareBitmap, BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied);
}
var source = new Windows.UI.Xaml.Media.Imaging.SoftwareBitmapSource();
await source.SetBitmapAsync(softwareBitmap);
return;
}
catch (Exception err)
{
switch (err.HResult)
{
case unchecked((int)0x88982F81): //WINCODEC_ERR_UNSUPPORTEDOPERATION
// If the encoder does not support writing a thumbnail, then try again
// but disable thumbnail generation.
encoder.IsThumbnailGenerated = false;
break;
default:
throw err;
}
}
if (encoder.IsThumbnailGenerated == false)
{
await encoder.FlushAsync();
}
}
return;
}
catch (Exception)
{
return;
}
finally
{
GC.Collect();
}
}
private async Task<Windows.Storage.Streams.IInputStream> GetThumbnailAsync(StorageFile file)
{
var mediaClip = await Windows.Media.Editing.MediaClip.CreateFromFileAsync(file);
var mediaComposition = new Windows.Media.Editing.MediaComposition();
mediaComposition.Clips.Add(mediaClip);
return await mediaComposition.GetThumbnailAsync(
TimeSpan.Zero, 0, 0, Windows.Media.Editing.VideoFramePrecision.NearestFrame);
}
}

C# UWP Camera Cannot find the file specified

I'm trying to get this mini app to save the photo taken by the camera but I get this error.System.IO.FileNotFoundException: 'The system cannot find the file specified. (Exception from HRESULT: 0x80070002)'
I followed the Microsoft Tutorial but cant get it to work.
private async void btnTakePhoto_Click(object sender, RoutedEventArgs e)
{
CameraCaptureUI captureUI = new CameraCaptureUI();
captureUI.PhotoSettings.Format = CameraCaptureUIPhotoFormat.Jpeg;
captureUI.PhotoSettings.CroppedSizeInPixels = new Size(200, 200);
//StorageFile photo = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/mypic.jpg"));
StorageFile photo = await captureUI.CaptureFileAsync(CameraCaptureUIMode.Photo);
if (photo == null)
{
// User cancelled photo capture
return;
}
StorageFolder destinationFolder =
await ApplicationData.Current.LocalFolder.CreateFolderAsync("ProfilePhotoFolder",
CreationCollisionOption.OpenIfExists);
await photo.CopyAsync(destinationFolder, "ProfilePhoto.jpg", NameCollisionOption.ReplaceExisting);
await photo.DeleteAsync();
IRandomAccessStream stream = await photo.OpenAsync(FileAccessMode.Read);
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream);
SoftwareBitmap softwareBitmap = await decoder.GetSoftwareBitmapAsync();
SoftwareBitmap softwareBitmapBGR8 = SoftwareBitmap.Convert(softwareBitmap,
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Premultiplied);
SoftwareBitmapSource bitmapSource = new SoftwareBitmapSource();
await bitmapSource.SetBitmapAsync(softwareBitmapBGR8);
imageControl.Source = bitmapSource;
}

From the above mentioned code snippet remove the line that I have written below.
await photo.DeleteAsync();
After removing the line it works fine.

Get a new Image by cropping

I'm trying to convert my cropped image (and/or Grid) to new Normal Image , but it returns as it cropped , in same position, how to fix it, there is how works my program after cropping
private async void Save(object sender, RoutedEventArgs e)
{
RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap();
await renderTargetBitmap.RenderAsync(GGrid, 4096 , 2448);
// IBuffer pixels = await renderTargetBitmap.GetPixelsAsync();
IBuffer pixelBuffer = await renderTargetBitmap.GetPixelsAsync();
FileSavePicker fileSavePicker = new FileSavePicker();
fileSavePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
fileSavePicker.FileTypeChoices.Add("JPEG files", new List<string>() { ".png"});
fileSavePicker.SuggestedFileName = "image";
var outputFile = await fileSavePicker.PickSaveFileAsync();
if (outputFile == null)
{
// The user cancelled the picking operation
return;
}
using (IRandomAccessStream stream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
encoder.SetPixelData(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Straight,
(uint)renderTargetBitmap.PixelWidth,
(uint)renderTargetBitmap.PixelHeight,
DisplayInformation.GetForCurrentView().LogicalDpi,
DisplayInformation.GetForCurrentView().LogicalDpi,
pixelBuffer.ToArray());
try
{
await encoder.FlushAsync();
}
catch (Exception err)
{
switch (err.HResult)
{
case unchecked((int)0x88982F81): //WINCODEC_ERR_UNSUPPORTEDOPERATION
// If the encoder does not support writing a thumbnail, then try again
// but disable thumbnail generation.
encoder.IsThumbnailGenerated = false;
break;
default:
throw err;
}
}
//if (encoder.IsThumbnailGenerated == false)
//{
// await encoder.FlushAsync();
//}
}
}

You need to translate and crop the bitmap.
double x,y,w,h;
GGrid.RenderTransform = new TranslateTransform
{
X = -x, // translate back to origin (0,0)
Y = -y
};
RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap();
await renderTargetBitmap.RenderAsync(GGrid, w, h); // use crop size

how to copy an image from the filepicker into anotehr folder via an UWP app?

I need to copy an image from my windows universal app, I was able to pick an image from my gallery but i don't how to copy it in another folder.
Although I was able to display the image in my UWP interface, so I think that I succeed to get it as a stream.
Any help would be appreciated, I'm lost here ... here is the code I used:
public MainPage()
{
this.InitializeComponent();
// Scenario4WriteableBitmap = new WriteableBitmap((int)Scenario4ImageContainer.Width, (int)Scenario4ImageContainer.Height);
Scenario2DecodePixelHeight.Text = "100";
Scenario2DecodePixelWidth.Text = "100";
}
private async void buttonUpload_Click(object sender, RoutedEventArgs e)
{
int decodePixelHeight=150;
int decodePixelWidth=150;
// Try to parse an integer from the given text. If invalid, default to 100px
if (!int.TryParse(Scenario2DecodePixelHeight.Text, out decodePixelHeight))
{
Scenario2DecodePixelHeight.Text = "100";
decodePixelHeight = 100;
}
// Try to parse an integer from the given text. If invalid, default to 100px
if (!int.TryParse(Scenario2DecodePixelWidth.Text, out decodePixelWidth))
{
Scenario2DecodePixelWidth.Text = "100";
decodePixelWidth = 100;
}
FileOpenPicker open = new FileOpenPicker();
open.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
open.ViewMode = PickerViewMode.Thumbnail;
// Filter to include a sample subset of file types
open.FileTypeFilter.Clear();
open.FileTypeFilter.Add(".bmp");
open.FileTypeFilter.Add(".png");
open.FileTypeFilter.Add(".jpeg");
open.FileTypeFilter.Add(".jpg");
// Open a stream for the selected file
StorageFile file = await open.PickSingleFileAsync();
// Ensure a file was selected
if (file != null)
{
// Ensure the stream is disposed once the image is loaded
using (IRandomAccessStream fileStream = await file.OpenAsync(FileAccessMode.Read))
{
// Set the image source to the selected bitmap
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.DecodePixelHeight = decodePixelHeight;
bitmapImage.DecodePixelWidth = decodePixelWidth;
await bitmapImage.SetSourceAsync(fileStream);
Scenario2Image.Source = bitmapImage;
}
}
}
private async void submit_Click(object sender, RoutedEventArgs e)
{
String url = "http://localhost/mydatabase/add.php";
var values = new List<KeyValuePair<String, String>>
{
new KeyValuePair<string, string>("UserName",UserName.Text),
new KeyValuePair<string, string>("UserImage",UserImage.Text),
};
HttpClient client = new HttpClient();
HttpResponseMessage response = new HttpResponseMessage();
try
{
response = await client.PostAsync(url, new FormUrlEncodedContent(values));
/*client.DefaultRequestHeaders.Add("content_type", "binary/octet_stream");
responseImage = client.PostAsync("", FileChooser.FileName);*/
if (response.IsSuccessStatusCode)
{
Debug.WriteLine(response.StatusCode.ToString());
var dialog = new MessageDialog("added succesfully ");
await dialog.ShowAsync();
}
else
{
// problems handling here
string msg = response.IsSuccessStatusCode.ToString();
throw new Exception(msg);
}
}
catch (Exception exc)
{
// .. and understanding the error here
Debug.WriteLine(exc.ToString());
}
}
`

you can use CopyAsync of StorageFile to copy the file you get from FileOpenPicker to a specific folder.

Image source to writeablebitmap in windows phone 8.1

I'm working on windows phone 8.1 application. I have different pictures locally in app and displaying those pictures in list view. Now select one picture id and pass it to detail screen, where I have to save that file .
My detail.Xaml screen contain image control named as Imaged.
I got image on detail page and press image save button. I'm using this Sample app https://code.msdn.microsoft.com/windowsapps/Save-Edited-Picture-16d910c4/sourcecode?fileId=119937&pathId=946309183 "Sample"
My detail page Code is here.
string tempimg;
protected override void OnNavigatedTo(NavigationEventArgs e)
{
var imagePath = e.Parameter as string;
imaged.Source = new BitmapImage(new Uri(imagePath, UriKind.RelativeOrAbsolute));
tempimg = imagePath;
}
My SaveImage button code is here.
if (tempimg == null)
return;
// WriteableBitmap abc = new WriteableBitmap(400, 400);
string filename = "Image-" + DateTime.Now.ToFileTime() + ".jpeg";
// await SaveWriteableBitmapAsJpeg(img, filename);
Blockquote
await SaveWriteableBitmapAsJpeg(tempimg, filename);
private static async Task SaveWriteableBitmapAsJpeg(WriteableBitmap bmp, string fileName)
{
// Create file in Pictures library and write jpeg to it
var outputFile = await KnownFolders.CameraRoll.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
using (var writeStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
await EncodeWriteableBitmap(bmp, writeStream, BitmapEncoder.JpegEncoderId);
}
}
private static async Task EncodeWriteableBitmap(WriteableBitmap bmp, IRandomAccessStream writeStream, Guid encoderId)
{
// Copy buffer to pixels
byte[] pixels;
using (var stream = bmp.PixelBuffer.AsStream())
{
pixels = new byte[(uint)stream.Length];
await stream.ReadAsync(pixels, 0, pixels.Length);
}
// Encode pixels into stream
var encoder = await BitmapEncoder.CreateAsync(encoderId, writeStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied,
(uint)bmp.PixelWidth, (uint)bmp.PixelHeight,
96, 96, pixels);
await encoder.FlushAsync();
}
My this function "await SaveWriteableBitmapAsJpeg(tempimg, filename);" creates a problem. I just have the image source while that require the writeablebitmap. I just want to save image and not able to proceed from here. let me know the exact solution or problem.