Zxing qr code decode can't get it work - c#

I've searched all the forum and I cannot find the answer (and this is my first post, so sorry for possible errors).
I've downloaded Zxing pack and I would like to get the qr code decoder work (in c#, a WPF application). The problem is that I get no error while compiling, and the application goes well (I take the input stream from kinect rgb camera) but it seems it does nothing.
I report some code (probably I've made some error...):
RGBLuminanceSource ls = new RGBLuminanceSource(bit, frame.Width,frame.Height);
Result result = new QRCodeReader().decode(new BinaryBitmap(new HybridBinarizer(ls)));
if (result != null)
Console.WriteLine("yahoo!");
else
Console.WriteLine("oh no");
with frame that is the frame captured by the kinect, and bit is the byte[] array that RGBLuminanceSource want as input, and I've made it by this:
byte[] bit= new byte[frame.PixelDataLength];
colorFrame.CopyPixelDataTo(bit);
What pass is that, when I put the paper with the qr code in front of the camera, it always return me the message "oh no", and I cannot figure out what I'm doing wrong.

As far as I know the image which you get from the kinect camera is flipped.
You have to flip it back before decoding.
You can find some more detail here:
http://zxingnet.codeplex.com/discussions/401772

In case someone stumbles upon this question, There are few things you can check.
Download the QRCodeDecoder sample from ZXing git and have it at ready
Save your Bitmap file to a folder location.
Check whether the saved Image decodes correctly from the QRCodeDecoder.
If you are using this for a QR Code scanner via the webcam or other video source, check whether you are converting the bitmap image in the correct pixel format.
hope this helps

Related

Dynamic image assigned to live tile does not show?

I have a Windows Store app written in C# that works with photos. I want to show the last photo the user selected in the app in the medium size live tile (150 x 150). I am using the code below to do it. When I run the app I don't get any errors, but I don't see the selected photo in the live tile either. I know that I am doing at least some things right. I say this because if the user hasn't selected a photo yet, then I show a test image and I do see that image in the tile. But the test image comes from the app package using the ms-appx protocol, not from the app storage area.
I found a few SO posts on the subject but they are all for Windows Phone. I looked at the KnownFolders list for Windows Store app files, but nothing seemed to map to the SharedContent folder required for files meant for live tile use in Windows Phone. What is wrong with my code?
Note, the vvm.ActiveVideomark.GetThumbnail() call simply retrieves a bitmap as a WriteableBitmap object. As you can see in the code, I am resizing the image to the size required by the Medium live tile (150 x 150). ToJpegFileAsync() is an extension method that encodes a WriteableBitmap object to jpeg bytes and then writes those bytes to a file using the given file name. Both of these calls are well-tested and are not the source of the problem as far as I know.
TileUpdateManager.CreateTileUpdaterForApplication().Clear();
TileUpdateManager.CreateTileUpdaterForApplication().EnableNotificationQueue(true);
var tileXml = TileUpdateManager.GetTemplateContent(TileTemplateType.TileSquare150x150Image);
var tileImage = tileXml.GetElementsByTagName("image")[0] as XmlElement;
// Got a current photo?
if (vvm.ActiveVideomark == null)
// No, just show the regular logo image.
tileImage.SetAttribute("src", "ms-appx:///Assets/Logo.scale-100.png");
else
{
// Resize it to the correct size.
WriteableBitmap wbm = await vvm.ActiveVideomark.GetThumbnail();
WriteableBitmap wbm2 = wbm.Resize(150, 150, WriteableBitmapExtensions.Interpolation.Bilinear);
// Write it to a file so we can pass it to the Live Tile.
string jpegFilename = "LiveTile1.jpg";
StorageFile jpegFile = await wbm2.ToJpegFileAsync(jpegFilename);
// Yes, show the selected image.
tileImage.SetAttribute("src", jpegFile.Path);
}
The src attribute must contain a URI with ms-appx:///, ms-appdata:///local, or http[s]:// schemes. The StorageFile.Path property, as you're using with jpegFile.Path, is a local filesystem pathmame like c:\users\Robert\AppData... which won't be valid. So create your tile images in local app data, and then use ms-appdata:///local/ to refer to them in tile payloads.

Generating video from a sequence of images in C#

I have a task of generating video from a sequence of images in my app and while searching for that i found out that FFMPEG is able to do that.Can anyone provide me any tutorial or link which can guide me in right direction.I am a newbiew in this so please help appropriately guys.
Will appreciate any sort of help
I could not manage to get the above example to work. However I did find another library that works amazingly well once. Try via NuGet "accord.extensions.imaging.io", then I wrote the following little function:
private void makeAvi(string imageInputfolderName, string outVideoFileName, float fps = 12.0f, string imgSearchPattern = "*.png")
{ // reads all images in folder
VideoWriter w = new VideoWriter(outVideoFileName,
new Accord.Extensions.Size(480, 640), fps, true);
Accord.Extensions.Imaging.ImageDirectoryReader ir =
new ImageDirectoryReader(imageInputfolderName, imgSearchPattern);
while (ir.Position < ir.Length)
{
IImage i = ir.Read();
w.Write(i);
}
w.Close();
}
It reads all images from a folder and makes a video out of them.
If you want to make it nicer you could probably read the image dimensions instead of hard coding, but you got the point.
http://electron.mit.edu/~gsteele/ffmpeg/
http://www.codeproject.com/Articles/7388/A-Simple-C-Wrapper-for-the-AviFile-Library
http://ffmpeg.org/ffmpeg.html -> search for For creating a video from many images:
All the links are from this question on SO
Link related to FFMPEG in .net (From this question);
FFMpeg.NET
FFMpeg-Sharp
FFLib.NET
http://ivolo.mit.edu/post/Convert-Audio-Video-to-Any-Format-using-C.aspx
Other resources
Expression Encoder
VLC
I bit late but I have made a tutorial on how I solved my similar problem if you did not succeed yet: Image sequence to video stream?
Same question asked here.
The answer there points to here, which is not exactly what you're doing, but is easily configurable to do the job.

Required Qr code Detector sample using zxing

I'm a beginer in QR code application and now I'm trying to develop application to detect QR code in the image. but i count not find any reference/sample in it.I'm using Zbar crossing zxing library and C# for this .kindly guide me in this or refer me some sample code.
We've also experienced that it is hard to find working samples for zxing.Net. After combining some of them (I can't remember where we found them) and some trial and error we found this to be satisfactory (excerpt):
[DebuggerHidden]
string findQrCodeText(com.google.zxing.Reader decoder, Bitmap bitmap)
{
var rgb = new RGBLuminanceSource(bitmap, bitmap.Width, bitmap.Height);
var hybrid = new com.google.zxing.common.HybridBinarizer(rgb);
com.google.zxing.BinaryBitmap binBitmap = new com.google.zxing.BinaryBitmap(hybrid);
string decodedString = decoder.decode(binBitmap, null).Text;
return decodedString;
}
which is called by
findQrCodeText(new com.google.zxing.qrcode.QRCodeReader(), bitmap);
We do some image voodoo around that to obtain just a little better results, but I'm afraid can't disclose that. This piece of code is the zxing part, though.
We added the DebuggerHiddenAttribute because zxing throws and swallows tons of exceptions internally, which is a real PITA when running in debug mode.

How to capture screen to be video using C# .Net?

I know there are lots of question like this.
But I don't want to use the Windows media encoder 9 because it's a problem to get one, and then it is no longer supported.
I know that, one possibility is to capture lots of screenshots and create a video with ffmpeg but I don't want use third party executables.
Is there are a .net only solution?
the answer is the Microsoft Expression Encoder. It is according to my opinion the easiest way to record something on vista and windows 7
private void CaptureMoni()
{
try
{
Rectangle _screenRectangle = Screen.PrimaryScreen.Bounds;
_screenCaptureJob = new ScreenCaptureJob();
_screenCaptureJob.CaptureRectangle = _screenRectangle;
_screenCaptureJob.ShowFlashingBoundary = true;
_screenCaptureJob.ScreenCaptureVideoProfile.FrameRate = 20;
_screenCaptureJob.CaptureMouseCursor = true;
_screenCaptureJob.OutputScreenCaptureFileName = string.Format(#"C:\test.wmv");
if (File.Exists(_screenCaptureJob.OutputScreenCaptureFileName))
{
File.Delete(_screenCaptureJob.OutputScreenCaptureFileName);
}
_screenCaptureJob.Start();
}
catch(Exception e) { }
}
Edit Based on Comment Feedback:
A developer by the name baSSiLL has graciously shared a repository that has a screen recording c# library as well as a sample project in c# that shows how it can be used to capture the screen and mic.
Starting a screen capture using the sample code is as straight forward as:
recorder = new Recorder(_filePath,
KnownFourCCs.Codecs.X264, quality,
0, SupportedWaveFormat.WAVE_FORMAT_44S16, true, 160);
_filePath is the path of the file I'd like to save the video to.
You can pass in a variety of codecs including AVI, MotionJPEG, X264, etc. In the case of x264 I had to install the codec on my machine first but AVI works out of the box.
Quality only comes into play when using AVI or MotionJPEG. The x264 codec manages its own quality settings.
The 0 above is the audio device I'd like to use. The Default is zero.
It currently supports 2 wave formats. 44100 at 16bit either stereo or mono.
The true parameter indicates that I want the audio encoded into mp3 format. I believe this is required when choosing x264 as the uncompressed audio combined in a .mp4 file would not play back for me.
The 160 is the bitrate at which to encode the audio.
~~~~~
To stop the recording you just
recorder.Dispose();
recorder = null;
Everything is open source so you can edit the recorder class and change dimensions, frames per second, etc.
~~~~
To get up and running with this library you will need to either download or pull from the github / codeplex libraries below. You can also use NuGet:
Install-Package SharpAvi
Original Post:
Sharp AVI:
https://sharpavi.codeplex.com/
or
https://github.com/baSSiLL/SharpAvi
There is a sample project within that library that has a great screen recorder in it along with a menu for settings/etc.
I found Screna first from another answer on this StackoverFlow question but I ran into a couple issues involving getting Mp3 Lame encoder to work correctly. Screna is a wrapper for SharpAVI. I found by removing Screna and going off of SharpAvi's sample I had better luck.

Create Video out of image files?

I'm trying to make a video out of a folder full of jpeg files. I tried Google, and everybody is stuck with this. I have downloaded the WM SDK and the Encoder, but since the moment I don't know their object model I cant do much.
Does somebody here have some code WORKING about how to create a WMV or an AVI or a MPEG video file out of a folder full of jpegs? (In C#)
I can see on the answers that apparently there is no way to do it from C#, just using a third party. I will check your suggestions.
Take a look at Corinna John's AVIFile wrapper. I used it in the AVI output plugin for Cropper.
VirtualDub is capable of making a video out of several image files. Here's a quite overview of how to do it.
FFMPEG, as CptSkippy mentioned, also has this feature.
See the AVBlocks Slideshow sample. It creates a video (like MP4) from images. The input is a series of JPEG images. The output is configured with an AVBlocks preset.
Try via NuGet "accord.extensions.imaging.io", then I wrote the following little function:
private void makeAvi(string imageInputfolderName, string outVideoFileName, float fps = 12.0f, string imgSearchPattern = "*.png")
{ // reads all images in folder
VideoWriter w = new VideoWriter(outVideoFileName,
new Accord.Extensions.Size(480, 640), fps, true);
Accord.Extensions.Imaging.ImageDirectoryReader ir =
new ImageDirectoryReader(imageInputfolderName, imgSearchPattern);
while (ir.Position < ir.Length)
{
IImage i = ir.Read();
w.Write(i);
}
w.Close();
}
It reads all images from a folder and makes a video out of them.
If you want to make it nicer you could probably read the image dimensions instead of hard coding, but you got the point.
Have you considered using FFMPEG? I've used it to create thumbnails from video in several projects.
I finally settled on Splicer. Free, simple to use, and it works. More info at Working way to make video from images in C#

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