Develop Reference

Scan a code with xzing from a photo

I have a feature request. The current flow is for the user to scan a code (not a QR code, not sure what it is, zxing will scan it), then scan the test card.
The client has asked for me allow the user to import the test from the library. So we need to be able to scan the code off an image.
Is it possible to do this in zxing or am I forced to use the camera / feature is not possible?
Thanks!

Here is my solution. I had to downsize the image, and inver the colors for it to work with zxing. I might add a convert to gray scale, but not today..
public static String scanDataMatrixImage(Bitmap bitmap) {
bitmap = doInvert(bitmap);
double scaling = getScaling(bitmap);
Bitmap resized;
if(scaling>0) {
resized = Bitmap.createScaledBitmap(bitmap, (int) (bitmap.getWidth() * scaling), (int) (bitmap.getHeight() * scaling), true);
}
else{
resized = bitmap;
}
String contents = null;
int[] intArray = new int[resized.getWidth() * resized.getHeight()];
//copy pixel data from the Bitmap into the 'intArray' array
resized.getPixels(intArray, 0, resized.getWidth(), 0, 0, resized.getWidth(), resized.getHeight());
LuminanceSource source = new RGBLuminanceSource(resized.getWidth(), resized.getHeight(), intArray);
BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(source));
MultiFormatReader reader = new MultiFormatReader();
try
{
Result result = reader.decode(binaryBitmap);
contents = result.getText();
} catch (
Exception e
)
{
Log.e("QrTest", "Error decoding barcode", e);
}
return contents;
}
private static double getScaling(Bitmap bitmap){
int width = bitmap.getWidth();
int height = bitmap.getHeight();
int smallest = width;
if(smallest > height){
smallest = height;
}
double ratio = 200.0/smallest;
return ratio;
}
public static Bitmap doInvert(Bitmap src) {
// create new bitmap with the same settings as source bitmap
Bitmap bmOut = Bitmap.createBitmap(src.getWidth(), src.getHeight(), src.getConfig());
// color info
int A, R, G, B;
int pixelColor;
// image size
int height = src.getHeight();
int width = src.getWidth();
// scan through every pixel
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
// get one pixel
pixelColor = src.getPixel(x, y);
// saving alpha channel
A = Color.alpha(pixelColor);
// inverting byte for each R/G/B channel
R = 255 - Color.red(pixelColor);
G = 255 - Color.green(pixelColor);
B = 255 - Color.blue(pixelColor);
// set newly-inverted pixel to output image
bmOut.setPixel(x, y, Color.argb(A, R, G, B));
}
}
// return final bitmap
return bmOut;
}

Android-Ocr using Tesseract in Portrait

I used the ocr sample in this link https://github.com/rmtheis/android-ocr
Every thing is working fine but i want it in Portrait view,I followed the steps in this link , Zxing Camera in Portrait mode on Android, to enable ocr tesstow in Portrait mode . The View is portrait now but the camera is still taking the picture in landscape mode.
Any help ?
final class PreviewCallback implements Camera.PreviewCallback {
private static final String TAG = PreviewCallback.class.getSimpleName();
private final CameraConfigurationManager configManager;
private Handler previewHandler;
private int previewMessage;
PreviewCallback(CameraConfigurationManager configManager) {
this.configManager = configManager;
}
void setHandler(Handler previewHandler, int previewMessage) {
this.previewHandler = previewHandler;
this.previewMessage = previewMessage;
}
// (NV21) format.
#Override
public void onPreviewFrame(byte[] data, Camera camera) {
Point cameraResolution = configManager.getCameraResolution();
Handler thePreviewHandler = previewHandler;
if (cameraResolution != null && thePreviewHandler != null) {
Message message = thePreviewHandler.obtainMessage(previewMessage, cameraResolution.x,
cameraResolution.y, data);
message.sendToTarget();
previewHandler = null;
} else {
Log.d(TAG, "Got preview callback, but no handler or resolution available");
}
}

Are you using the preview data with this method:
public void onPreviewFrame(byte[] data, Camera camera) {}
If yes, then I can help you, since I am doing very similar project (that will be open sourced soon)
here is the code that I am using to rotate the preview image
public static Bitmap getBitmapImageFromYUV(byte[] data, int width,
int height, int degree, Rect rect) {
Bitmap bitmap = getBitmapImageFromYUV(data, width, height, rect);
return rotateBitmap(bitmap, degree,rect);
}
public static Bitmap rotateBitmap(Bitmap source, float angle, Rect rect) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
source = Bitmap.createBitmap(source, 0, 0, source.getWidth(),
source.getHeight(), matrix, true);
source = Bitmap.createBitmap(source, rect.left, rect.top, rect.width(), rect.height());
if(mShouldSavePreview)
saveBitmap(source);
return source;
}
public static Bitmap getBitmapImageFromYUV(byte[] data, int width,
int height, Rect rect) {
YuvImage yuvimage = new YuvImage(data, ImageFormat.NV21, width, height,
null);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
yuvimage.compressToJpeg(new Rect(0, 0, width, height), 90, baos);
byte[] jdata = baos.toByteArray();
BitmapFactory.Options bitmapFatoryOptions = new BitmapFactory.Options();
bitmapFatoryOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bmp = BitmapFactory.decodeByteArray(jdata, 0, jdata.length,
bitmapFatoryOptions);
Log.d(TAG,"getBitmapImageFromYUV w:"+bmp.getWidth()+" h:"+bmp.getHeight());
return bmp;
}

guys i found the solution!
Replace the next code in function: ocrDecode(byte[] data, int width, int height) in DecodeHandler.java file
beepManager.playBeepSoundAndVibrate();
activity.displayProgressDialog();
// *************SHARNOUBY CODE
byte[] rotatedData = new byte[data.length];
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++)
rotatedData[x * height + height - y - 1] = data[x + y * width];
}
int tmp = width;
width = height;
height = tmp;
//******************************
// Launch OCR asynchronously, so we get the dialog box displayed
// immediately
new OcrRecognizeAsyncTask(activity, baseApi, rotatedData, width, height)
.execute();
...the problem was in the switch case in the function handleMessage(Message message)
the second case was never triggered which calls the rotation code

OnPreviewFrame data image to imageView

i'm trying to get the byte[] from the preview of the camera, convert it to bitmap and display it on a imageview with imageView.setImageBitmap()
i've managed to start the preview and display it on a surfaceView, but i don't know how to convert the byte[] data (that comes in Yuv format i think) in a RGB bitmap to display it on a imageView.
the code i'm trying is the following:
camera = camera.open();
parameters = camera.getParameters();
camera.setParameters(parameters);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
camera.setPreviewDisplay(surfaceHolder);
camera.setPreviewCallback(this);
camera.startPreview();
and the preview callback is this
#Override
public void onPreviewFrame(byte[] data, Camera camera) {
Camera.Parameters parameters = camera.getParameters();
int width = parameters.getPreviewSize().width;
int height = parameters.getPreviewSize().height;
ByteArrayOutputStream outstr = new ByteArrayOutputStream();
Rect rect = new Rect(0, 0, width, height);
YuvImage yuvimage=new YuvImage(data,ImageFormat.NV21,width,height,null);
yuvimage.compressToJpeg(rect, 100, outstr);
Bitmap bmp = BitmapFactory.decodeByteArray(outstr.toByteArray(), 0, outstr.size());
imgView1.setImageBitmap(bmp);
}
The preview works but the imageView remains empty
Any idea?

It is possible you did not open the Camera in the UI thread. However, you need to ensure setImageBitmap is called in the UI thread:
#Override
public void onPreviewFrame(final byte[] data, Camera camera) {
Camera.Parameters parameters = camera.getParameters();
int width = parameters.getPreviewSize().width;
int height = parameters.getPreviewSize().height;
YuvImage yuv = new YuvImage(data, parameters.getPreviewFormat(), width, height, null);
ByteArrayOutputStream out = new ByteArrayOutputStream();
yuv.compressToJpeg(new Rect(0, 0, width, height), 50, out);
byte[] bytes = out.toByteArray();
final Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
MyActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
((ImageView) findViewById(R.id.loopback)).setImageBitmap(bitmap);
}
});
}

How to adjust image brightness in Android with OpenCV?

I created an example image with brightness adjusted in Android. I used Bitmap to adjust the brightness but it takes a very long time to run. Instead, I want to set the image brightness in Android using OpenCV.
This is my example code, but it only changes the colour of the image:
Bitmap bmp = BitmapFactory.decodeResource(getResources(),
R.drawable.a001);
int width = bmp.getWidth();
int height = bmp.getHeight();
Mat mRgba = new Mat(width, height, CvType.CV_8UC1);
Utils.bitmapToMat(bmp, mRgba);
Mat mRay = new Mat();
Imgproc.cvtColor(mRgba, mRay, Imgproc.COLOR_BGRA2RGB, 4);
Utils.matToBitmap(mRay, bmp);
mImageview_01.setImageBitmap(bmp);
[Update]
I try add code, but it error
Bitmap bmp = BitmapFactory.decodeResource(getResources(),
R.drawable.a001);
int width = bmp.getWidth();
int height = bmp.getHeight();
Mat mRgba = new Mat(width, height, CvType.CV_8UC1);
Utils.bitmapToMat(bmp, mRgba);
Mat mRay = new Mat();
Imgproc.cvtColor(mRgba, mRay, Imgproc.COLOR_BGRA2RGB, 4);
/*
* Use Adaptive Thresholding on the grayscaled Mats crop -> threshed Mat
* src, Mat dst, double maxValue, int adaptiveMethod, int thresholdType,
* int blockSize, double C
*/
Imgproc.adaptiveThreshold(threshed, threshed, 255,
Imgproc.ADAPTIVE_THRESH_GAUSSIAN_C, Imgproc.THRESH_BINARY_INV, 15, 8);
Utils.matToBitmap(mRay, bmp);
mImageview_01.setImageBitmap(bmp);
[Error]
CvException [org.opencv.core.CvException: /home/reports/ci/slave_desktop/50-SDK/opencv/modules/imgproc/src/thresh.cpp:796: error: (-215) src.type() == CV_8UC1 in function void cv::adaptiveThreshold(cv::InputArray, cv::OutputArray, double, int, int, int, double)
Pls view examples of what I'm trying to do here.

There is many fast and easy ways to adjust a bitmap brightness, such as ColorMatrix or RenderScript. But if you still considered to use OpenCV that's the way :
private Bitmap changeBrightness(Bitmap bmp, int value){
Mat src = new Mat(bmap.getHeight(),bmap.getWidth(), CvType.CV_8UC1);
Utils.bitmapToMat(bmap,src);
src.convertTo(src,-1,1,value);
Bitmap result = Bitmap.createBitmap(src.cols(),src.rows(), Bitmap.Config.ARGB_8888);
Utils.matToBitmap(src,result);
return result;
}

check the example given at Increase/Decrease Brightness of Image
pls see this
int brightness;
SeekBar seekBarBrightness=(SeekBar)findViewById(R.id.seekBar1);
seekBarBrightness.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
#Override
public void onStopTrackingTouch(SeekBar arg0) {
}
#Override
public void onStartTrackingTouch(SeekBar arg0) {
}
#Override
public void onProgressChanged(SeekBar arg0, int progress, boolean arg2) {
Bitmap newBitMap = doBrightness(bitMap,progress);
imageView.setImageBitmap(newBitMap);
}
});
public static Bitmap doBrightness(Bitmap src, int value)
{
// image size
int width = src.getWidth();
int height = src.getHeight();
// create output bitmap
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
// color information
int A, R, G, B;
int pixel;
// scan through all pixels
for (int x = 0; x < width; ++x)
{
for (int y = 0; y < height; ++y)
{
// get pixel color
pixel = src.getPixel(x, y);
A = Color.alpha(pixel);
R = Color.red(pixel);
G = Color.green(pixel);
B = Color.blue(pixel);
// increase/decrease each channel
R += value;
if (R > 255)
{
R = 255;
} else if (R < 0)
{
R = 0;
}
G += value;
if (G > 255)
{
G = 255;
} else if (G < 0)
{
G = 0;
}
B += value;
if (B > 255)
{
B = 255;
} else if (B < 0)
{
B = 0;
}
// apply new pixel color to output bitmap
bmOut.setPixel(x, y, Color.argb(A, R, G, B));
}
}
// return final image
return bmOut;
}

How can i to get color/alpha of pixel from Sprite in andengine?

How can i to get color/alpha of pixel from Sprite in andengine without creating any additional Bitmap?

I solved this problem by using this function
private void loadObjectsMask()
{
InputStream in = null;
Bitmap maskForObjects=null;
try {
final BitmapFactory.Options decodeOptions = new BitmapFactory.Options();
decodeOptions.inPreferredConfig = Bitmap.Config.ARGB_4444;
in = GameActivity.this.getAssets().open("images/" + BACKGROUND_PATH + getObjectImgFile());
maskForObjects = BitmapFactory.decodeStream(in, null, decodeOptions);
} catch (final IOException e) {
} finally {
StreamUtils.close(in);
}
if (maskForObjects != null)
{
objectsMask=new byte[maskForObjects.getWidth()][maskForObjects.getHeight()];
for(int pw=0;pw<maskForObjects.getWidth();++pw)
{
for(int ph=0;ph<maskForObjects.getHeight();++ph)
{
objectsMask[pw][ph]=(byte)(Color.alpha(maskForObjects.getPixel(pw, ph))==0?0:1);
}
}
maskForObjects.recycle();
System.out.printf("Bitmap size %d %d\n", maskForObjects.getWidth(),maskForObjects.getHeight());
}
else System.out.printf("Bitmap size error\n");
}

have a look this method, this method are used to effect on each pix
public Bitmap invert(Bitmap src) {
// image size
int width = src.getWidth();
int height = src.getHeight();
// create output bitmap
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
// color information
int A, R, G, B;
int pixel;
// scan through all pixels
for(int x = 0; x < width; ++x) {
for(int y = 0; y < height; ++y) {
// get pixel color
pixel = src.getPixel(x, y);
// get color on each channel
A = Color.alpha(pixel);
R = Color.red(pixel);
G = Color.green(pixel);
B = Color.blue(pixel);
// set new pixel color to output image
bmOut.setPixel(x, y, Color.argb(A, 255-R, 255-G, 255-B));
}
}
// return final image
return bmOut;
}
To convert Gray Scale
public static Bitmap toGrayscale(Bitmap bmpOriginal)
{
int width, height;
height = bmpOriginal.getHeight();
width = bmpOriginal.getWidth();
Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
Canvas c = new Canvas(bmpGrayscale);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
cm.setSaturation(0);
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
c.drawBitmap(bmpOriginal, 0, 0, paint);
return bmpGrayscale;
}