camera - Android: mPrevCallback to JPG, results in black pictures -

i trying capture preview of camera on surfaceview ,to save jpeg in internal memory. found code here on site, want saves image sd card. changed that, , came following code.

camera.previewcallback mprevcallback = new camera.previewcallback() {     @override     public void onpreviewframe( byte[] data, camera cam ) {         //log.d(tag, "frame");         camera.parameters parameters = cam.getparameters();         int format = parameters.getpreviewformat();         //log.d(tag, "format:" + format);         //yuv formats require more conversion         if (format == imageformat.nv21 || format == imageformat.yuy2 || format == imageformat.nv16) {             int w = parameters.getpreviewsize().width;             int h = parameters.getpreviewsize().height;             // yuv image             yuvimage yuv_image = new yuvimage(data, format, w, h, null);             // convert yuv jpeg             rect rect = new rect(0, 0, w, h);             bytearrayoutputstream output_stream = new bytearrayoutputstream();             yuv_image.compresstojpeg(rect, 100, output_stream);             byte[] byt = output_stream.tobytearray();             fileoutputstream outstream = null;             try {                 outstream = new fileoutputstream("/data/data/com.example.max.camtest/files/test"+system.currenttimemillis()+".jpg");                 outstream.write(byt);                 outstream.close();              } catch (filenotfoundexception e) {                 e.printstacktrace();             } catch (ioexception e) {                 e.printstacktrace();             } {             }           }     } }; 

the preview shown on surfaceview , mprevcallback triggered.it saves pictures have diffrent sizes (250~500kb) black. when try capture picture camera.takepicture function black.

what doing wrong? how can debug this? thanks!

use intent take picture

            intent intent = new intent(mediastore.action_image_capture);             file f = new file(android.os.environment.getexternalstoragedirectory(), appinfo.getinstance().getcurrentloginuserinfo().getid()+".jpg");             intent.putextra(mediastore.extra_output, uri.fromfile(f));             intent.putextra("return-data", true);             startactivityforresult(intent, 1); 

and on activity result.... note bitmap bitmap = getscaledbitmap(uri.getpath(), 200, true); 200 max image size.

if(requestcode == 1)         { string base = environment.getexternalstoragedirectory().getabsolutepath().tostring();             final string imgpath = base + "/" +appinfo.getinstance().getcurrentloginuserinfo().getid()+".jpg";             file file = new file(imgpath);             if (file.exists())              {                 uri uri = uri.fromfile(file);              log.d(tag, "image uri path: " + uri.getpath());              bitmap bitmap = getscaledbitmap(uri.getpath(), 200, true);          }} 

this method ll return image bitmap after resizing it-

private bitmap getscaledbitmap(string imagepath, float maximagesize, boolean filter) {  fileinputstream in; bufferedinputstream buf;  try {     in = new fileinputstream(imagepath);      buf = new bufferedinputstream(in);     bitmap realimage = bitmapfactory.decodestream(buf);       float ratio = math.min(             (float) maximagesize / realimage.getwidth(),             (float) maximagesize / realimage.getheight());      int width = math.round((float) ratio * realimage.getwidth());     int height = math.round((float) ratio * realimage.getheight());      bitmap newbitmap = bitmap.createscaledbitmap(realimage, width, height, filter);     return newbitmap;  } catch (filenotfoundexception e) {     // todo auto-generated catch block     e.printstacktrace(); }  return null; } 

now have scaled bitmap image.

hope ll you.