public void OnPreviewFrame (byte[] data, Camera camera)
{
var parameters = camera.GetParameters ();
var size = parameters.PreviewSize;
var barcode = new Image (size.Width, size.Height, "Y800");
barcode.SetData (data);
var result = scanner.ScanImage (barcode);
if (result == 0)
return;
camera.SetPreviewCallback (null);
camera.StopPreview ();
var scannerResult = GetScannerResult ();
ScanComplete?.Invoke (this, new ScanCompleteEventArgs (scannerResult));
}
/// <summary>
/// Capture and scan images
/// </summary>
/// <remarks>
/// This method will also flip the images so that they need not be flipped when drawing.
/// </remarks>
private void CaptureVideo(Video video, ImageScanner scanner)
{
while (true)
{
using (ZBar.Image frame = video.NextFrame()){
using (ZBar.Image bwImg = frame.Convert(0x30303859)){
//Scan the image for bar codes
scanner.Scan(bwImg);
//Get the data, width, height and symboles for the image
byte[] data = bwImg.Data;
int w = (int)bwImg.Width;
int h = (int)bwImg.Height;
var symbols = new List <Symbol> (bwImg.Symbols);
// Resize
// number of pixels to shift in the original image
double stepX = (double)w / AllocatedWidth;
double stepY = (double)h / AllocatedHeight;
// don't do enlarging
if (stepX <= 1 && stepY <= 1)
{
return;
}
double smallestStep = Math.Max(stepX, stepY);
stepX = stepY = smallestStep;
int maxHeight = (int)((double)h / smallestStep);
int maxWidth = (int)((double)w / smallestStep);
int newPixels = maxWidth * maxHeight;
byte[] resizedFrame = new byte[newPixels];
double sX = 0, sY = 0;
int i;
for (int j = 0; j < newPixels; j++)
{
i = (int)sX + (int)((int)sY * w);
// stop exceptions
if (i >= data.Length)
{
Console.WriteLine("Trying to access {0} on the old frame, up to {1} on new frame", i, j);
break;
}
resizedFrame[j] = data[i];
sX += stepX;
if ((j + 1) % maxWidth == 0)
{
sY += stepY;
sX = 0;
}
}
w = maxWidth;
h = maxHeight;
data = resizedFrame;
//Flip the image vertically, if needed
if (this.Flip)
{
for (int ih = 0; ih < h; ih++)
{
for (int iw = 0; iw < w / 2; iw++)
{
//TODO: The offsets below could be computed more efficiently, but I don't care this happens on a thread... :)
int p1 = w * ih + iw;
int p2 = w * ih + (w - iw - 1);
//Swap bytes:
byte b1 = data[p1];
data[p1] = data[p2];
data[p2] = b1;
}
}
}
if (Rotate)
{
int l = data.Length - 1;
for (int p = 0; p < data.Length / 2; p++)
{
//Swap bytes:
var j = l - p;
byte b1 = data[j];
data[j] = data[p];
data[p] = b1;
}
}
//Lock the drawing process and pass it the data we aquired
lock (this.drawLock){
this.toDraw = data;
this.toDrawWidth = w;
this.toDrawHeight = h;
this.symbols = symbols;
}
this.ThreadSafeRedraw();
}
}
}
}
public void ScanEan13_SymbolEnabled() {
//var rawImage = System.IO.File.ReadAllBytes ("../ean13.png");
var bitmap = Android.Graphics.BitmapFactory.DecodeFile ("../ean13.png");
var image = new Image (bitmap.Width, bitmap.Height, "Y800");
image.SetData (bitmap.ToArray<byte>());
var scanner = new ImageScanner ();
scanner.DisableSymbols (SymbolType.None);
scanner.EnableSymbols (SymbolType.Ean13);
var result = scanner.ScanImage (image);
Assert.True (result > 0);
var symbols = scanner.Results;
foreach (var symbol in symbols) {
Assert.AreEqual (symbol.Type, SymbolType.Ean13);
Assert.AreEqual (symbol.Data, "2398000012344");
}
}
