Our company has an application that receives bitonal TIFF images via fax or scanner and saves them to a database; currently, we display the images from the database using an ActiveX control, but now we want to use a Silverlight control to display those images instead. However, we are not able to display or save the images as bitonal TIFF images; using the following code in our ashx handler, we get a blank image:
pageno = Convert.ToInt32(context.Request.QueryString("page"))
'Get image data from database
Dim bmp() As Byte = ShowDocumentImage(documentID)
'Get current page of TIFF image as bitmap
Dim newBmp As Bitmap = GetTifPage(bmp, pageno)
Dim info As Imaging.ImageCodecInfo = Nothing
Dim ice As Imaging.ImageCodecInfo
For Each ice In Imaging.ImageCodecInfo.GetImageEncoders()
If ice.MimeType = "image/tiff" Then
info = ice
End If
Next
Dim enc As Imaging.Encoder = Imaging.Encoder.SaveFlag
Dim ep As New Imaging.EncoderParameters(2)
ep.Param(0) = New Imaging.EncoderParameter(enc, CLng(Imaging.EncoderValue.MultiFrame))
ep.Param(1) = New Imaging.EncoderParameter(enc, CLng(Imaging.EncoderValue.CompressionCCITT4))
If newBmp IsNot Nothing Then
newBmp.Save(context.Response.OutputStream, info, ep)
newBmp.Dispose()
End If
Instead, we have to save them as JPEG, which does display to the user but which also increases the bit depth and the size of the files; it also increases the time it takes to save the image. It takes about 6 seconds to convert a 1728x2079 JPEG to a byte array so that it can be uploaded to the database.
Is there a way to display and save the image as a bitonal TIFF, and/or a faster way to convert the image to a byte array?
As far as I know, support for TIFF images in Silverlight is very limited.
There are 3-rd party libraries that can help you with your task. I am personally recommend you to try LibTiff.Net library. The library is completely free (even for commercial use) and open source.
Source code package of LibTiff.Net contains Silverlight Test Application that shows how to asynchronously load and display TIFF images in a Silverlight app. It can display various TIFF flavors including bitonal ones.
You might find this answer to a similar question useful too.
Related
I am using birt to develop some reports,I want to display some pie charts in the birt pdf report,I found the birt chart function is not very flexiable,so I want to use jfreechart to generate an image and show it in the report instead. Now I have a question: can we show image in birt with the image inputstream,so that the image do not need to be generated and store in some place?
I know I can generate the image into a jpg file and store it in some place ,then I can access it birt report via the location of this image file.But if I do as that ,each time when we view the birt report ,it will generate a new image file,I do not want to generate so much files.
Any good ideas?
There are two possible solutions.
As you said, you can save the charts as files.
I do this in a report where I generate dozens of control charts (German: "Regelkarten"). To tidy up after the report has finished, I add the generated file names to a list, then I delete the files in the list in the report's afterRender script like this.
var images = vars["images"];
for (var i=0; i<images.size(); i++) {
var fname = images.get(i);
if (new java.io.File(fname)['delete']()) {
log.debug("Temp. image file removed: " + fname);
} else {
log.error("Could not delete temp. image file " + fname);
}
}
Note: This is OK for generating PDF or Word, but probably it wouldn't work for HTML.
In my case, I did this because I could check the generated charts outside of BIRT by just commenting out the clean up routine.
The other option is to generate a byte[]. BIRT complains in the log file then (Rhino, something about unknown type mapping Java<->Javascript), but it works.
I never have used this with JFreeChart, but that's how we do it for generating DataMatrix ("2D-Barcode") with an ancient commercial Java library from a company called "ID Automation".
The image item references row["dataMatrix_AuftID"], which is defined as type: Java Object, expression: barcode.dataMatrix(row["AUFT_ID"],70,70,80,0.03)
The function barcode.dataMatrix in our Javascript wrapper library for the Java library calls the Java library. Its last few lines look like this, which should give you an idea for your case:
var image = new java.awt.image.BufferedImage(siz.width, siz.height, t);
// get graphic context of image
var imgGraphics = image.createGraphics();
// paint DataMatrix in graphics context of image
bc.paint(imgGraphics);
// get the image's bytes in PNG format
var baos = new java.io.ByteArrayOutputStream();
javax.imageio.ImageIO.write(image, "png", baos);
var bytes = baos.toByteArray();
return bytes;
As a side-note, for a proof of concept I showed that it is also possible to generate SVG in memory and use it with BIRT. Never used this in production, however.
I have a situation in a Flex web app where we use a PHP webservice to lookup, read the contents and then send the Base64 encoded data back to the Flex app as part of an XML document.The Flex app must then extract, Base64 decode the byte stream and then send it DIRECTLY to the browser user (for download) without writing the file to disk.
This all must occur on the click of a "DOWNLOAD NOW" button for example.
I have been searching but all I have been finding are examples of either downloading from a URL or actually writing the byte stream to disk, which i don't want.
I need to get the stream pushed directly to the browser. This way i can keep the files on the server protected by being outside the webspace as opposed to publicly accessible.
Can anyone help?
You can pop a ByteArray into a Loader then use FileReference to initiate the download dialog.
var file:FileReference = new FileReference();
var loader:Loader = new Loader();
//put loader in binary mode
loader.dataFormat = URLLoaderDataFormat.BINARY;
loader.addEventListener(Event.COMPLETE, loader_completeHandler);
//I will assume you are getting an appropriate ByteArray from your stream
var data:ByteArray = new ByteArray();
loader.loadBytes(data);
private function loader_completeHandler(evt:Event):void {
//now pop a save window
file.save(loader.data,"default_file_name.png")
}
edit
I will also assume you are doing this to stream a file through a non standard protocol, such as AMF, otherwise you would simply output the file over HTTP and let the browser handle the rest.
I did a lot of research and came up with the code below. It successfully translates speech to text using the microphone.
I have a file on my webserver that streams audio via mp3. It is just a link to an mp3 file. I need to have that translated to text.
I am trying to figure out the best way to do this. So, can you select the audio input as the computers audio (ie play the audio in the web browser)? Or can you stream the audio directly to the translator? I think I need to use SetInputToWaveStream method, but do not understand how to use it.
Private Sub InitializeRecognizerSynthesizer()
Dim selectedRecognizer = ( _
Where e.Culture.Equals(Thread.CurrentThread.CurrentCulture)).FirstOrDefault()
recognizer = New SpeechRecognitionEngine(selectedRecognizer)
recognizer.AudioStateChanged += New EventHandler(Of AudioStateChangedEventArgs)(recognizer_AudioStateChanged)
recognizer.SpeechHypothesized += New EventHandler(Of SpeechHypothesizedEventArgs)(recognizer_SpeechHypothesized)
recognizer.SpeechRecognized += New EventHandler(Of SpeechRecognizedEventArgs)(recognizer_SpeechRecognized)
synthesizer = New SpeechSynthesizer()
End Sub
Private Function SelectInputDevice() As Boolean
Dim proceedLoading As Boolean = True
If IsOscompatible() Then
Try
recognizer.SetInputToDefaultAudioDevice()
Catch
'no audio input device
proceedLoading = False
End Try
Else
ThreadPool.QueueUserWorkItem(InitSpeechRecogniser)
End If
Return proceedLoading
End Function
recognizer.SetInputToWaveFile(file) - will read the audio input from a file in the file system.
recognizer.SetInputToAudioStream - will read the audio input from a stream. A short example:
FileStream fs = new FileStream(filename, FileMode.Open, FileAccess.Read);
SpeechAudioFormatInfo format = new SpeechAudioFormatInfo(8000, AudioBitsPerSample.Sixteen, AudioChannel.Mono);
recognizer.SetInputToAudioStream(fs, format);
When reading from a stream or a file you must use care to make sure that the audio data is in a supported format. For example, one format I know works on my machine is:
8 bits per sample
single channel mono
22,050 samples per second
PCM encoding
See Help with SAPI v5.1 SpeechRecognitionEngine always gives same wrong result with C# for more info about audio formats.
If your question is how to fetch a resource from a web server and handle it as a stream, see HttpWebResponse.GetResponseStream - http://msdn.microsoft.com/en-us/library/system.net.httpwebresponse.getresponsestream(v=vs.100).aspx
I have a Firbird 1.0 data file weighting aprox 25 GB that I am working with it. It has a table which has stored documents and doc's pics as blob. So, I am asking is it possible to open such big data file using fib datasets, i firstly tried to open dataset in runtime = no success as grid was empty so another try was to set it active in design mode which it was also unable to open as it's active property is set to true but no fetched data in grid!
Have you any idea to make it work ? Do I have to set any blob cashe options?
or it is not possible at all?
Now I am developing using my laptop computer (Win 7 x64 4GB Ram ), and later it'll be deployed to my server machine!
I've fixed it!
So another my question is about loading blob data using stream to a TImage component
i am doing like this but it pops out an Access violation
here is my code which you may look at
DM->stImage->Active=true;
try {
TMemoryStream *ms=new TMemoryStream();
TStream *ps=DM->stImage->CreateBlobStream(DM->stImage->FieldByName("PHOTO") ,bmRead);
ms->Position=0;
ms->CopyFrom(ps,ps->Size);
ms->SaveToFile("c:\\1.jpg");
// imgPass->Picture->LoadFromStream(ms);
imgPass->Picture->Graphic->LoadFromStream(ps);
delete ms;
delete ps;
}
catch (Exception &e) {
ShowMessage(e.ToString());
}
it can save it but imgPass->Picture->Graphic->LoadFromStream(ps); does not work!
what could be a problem?
To avoid the AV you need to reset the stream position, that was moved forward during the call to "CopyFrom" function.
So, your code should look like (only the relevant lines):
ms->CopyFrom(ps,ps->Size);
ms->SaveToFile("c:\\1.jpg");
ps->Position = 0; //<<<<<<<<<< here we reset the stream position
imgPass->Picture->Graphic->LoadFromStream(ps);
//imgPass->Picture->Bitmap->LoadFromStream(ps); // <<< if a bitmap and not JPEG
Hope this helps you.
P.S.: this question should be tagged C++ (or C++Builder) because it is not only a database subject.
I'm working with a ComponentOne (C1) silverlight PDF viewer control.
It has a "LoadDocument" method that accepts a "Stream".
I'm making an HTTP get call from my client app to get a PDF document.
This document, on the server side, has been streamed in through File.ReadAllBytes(), then converted to a base64 string using Convert.ToBase64String().
This string is sent across the wire back to my silverlight app where it's then reversely converted back into a byte array with Convert.FromBase64String(val).
Then I'm creating a MemoryStream with that byte array and passing "LoadDocument()" that memory stream.
The viewer is rendering nothing. It shows the toolbar and scrollbars, but the contents are blank and the save button is grayed out, suggesting that no document loaded.
I know for certain the file made it across because the byte array size on the client matches teh byte array pre-conversion on the server side.
Here's my code: (in the interest of time/space, i've truncated, removing validation, etc.)
SERVERSIDE
string sendingToClient = Convert.ToBase64String(File.ReadAllBytes(filePath))
CLIENTSIDE
byte[] image = null;
image = Convert.FromBase64String(stringFromServerCall);
MemoryStream stream = new MemoryStream(image);
docViewer.LoadDocument(stream);
edit As a potential workaround, I attempted to save the file into isolated storage with a ".pdf" extension. Then I use the IsolatedStorageFileStream to send to LoadDocument().
I've come to an actual error, it now says "PdfParserException was unhandled by user code: invalid file format (missing pdf header)"
Can anyone shed some light on this PDF header?
Here is an experiment I would conduct.
Add a button to your Xaml and on click use OpenFileDialog to get a FileInfo. From that FileInfo use its Open method to get a stream and pass that to docViewer.LoadDocument.
Now run it, click the button and select the same PDF document you are trying to send from the server.
If that succeeds you need to continue investigating your server streaming strategy. On the other hand if you still have the same problem, well it doesn't get more raw than that. Try other PDF files and start investigating the PDF component. Have you ever actually used it successfully, if so how does this current usage differ.
you should get the stream pointer back to 0 ,so this should do the trick
byte[] image = null;
image = Convert.FromBase64String(stringFromServerCall);
MemoryStream stream = new MemoryStream(image);
stream.Position = 0;
docViewer.LoadDocument(stream);