add comment about NV21. Fixes card-io#9

COCUSAG · Mar 16, 2015 · 5b34144 · 5b34144
1 parent a1edf80
commit 5b34144
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/card.io/src/main/jni/nativeRecognizer.cpp b/card.io/src/main/jni/nativeRecognizer.cpp
@@ -327,7 +327,10 @@ JNIEXPORT void JNICALL Java_io_card_payment_CardScanner_nScanFrame(JNIEnv *env,
     IplImage *cbcr = cvCreateImageHeader(cvSize(width / 2, height / 2), IPL_DEPTH_8U, 2);
     cbcr->imageData = ((char *)jBytes) + width * height;
     IplImage *cb, *cr;
+
+    // Note: cr and cb are reversed here because Android uses android.graphics.ImageFormat.NV21. This is actually YCrCb rather than YCbCr!
     dmz_deinterleave_uint8_c2(cbcr, &cr, &cb);
+
     cvReleaseImageHeader(&cbcr);
 
     dmz_edges found_edges;