talregev / android_cv_bridge Goto Github PK

First I want to apologise if this not the right place to raise this query.

I am developing an android app. to show a video stream from a camera on a robot. I have done this successfully using ROSImageView linked to a ROS compressedImage topic using ROSJava.

Now I want to try the same approach used by the cv_bridgeCompressedImage app. adapting the code for my Android app. I still don't understand github nor how to get from this code to a dependency in my build.gradle in my app. Is there a step-by-step set of instructions for beginners that you can refer me to?

I open a project in Android Studio but I am unsure what to do next. I run 'Make Project' and get this error: 'SDK location not found. Define location with sdk.dir in the local.properties file or with an ANDROID_HOME environment variable.'

Again, I am sorry if this is not an 'issue', I cam trying to get somewhere but I'm frustrated by coming up to 'brick walls'.

I am trying to run your tutorial on android_cv_bridge but it is throwing following error.
I am subscribing the image topic(/camera/rgb/image_color) from kinect in android phone. I ahve made my laptop as master and android phone as client.

org.ros.android.android_tutorial_cv_bridge E/roid_tutorial_cv_bridge﹕ cv_bridge exception: Unrecognized image encoding [bgr8]
org.ros.android.android_tutorial_cv_bridge E/art﹕ No implementation found for void org.opencv.core.Mat.n_delete(long) (tried Java_org_opencv_core_Mat_n_1delete and Java_org_opencv_core_Mat_n_1delete__J)
org.ros.android.android_tutorial_cv_bridge E/System﹕ Uncaught exception thrown by finalizer
org.ros.android.android_tutorial_cv_bridge E/System﹕ java.lang.UnsatisfiedLinkError: No implementation found for void org.opencv.core.Mat.n_delete(long) (tried Java_org_opencv_core_Mat_n_1delete and Java_org_opencv_core_Mat_n_1delete__J)
at org.opencv.core.Mat.n_delete(Native Method)
at org.opencv.core.Mat.finalize(Mat.java:2475)
at java.lang.Daemons$FinalizerDaemon.doFinalize(Daemons.java:191)
at java.lang.Daemons$FinalizerDaemon.run(Daemons.java:174)
at java.lang.Thread.run(Thread.java:818)

Hi, @talregev ! I'm new to ros and, recently I need transport a local image(from SD card) to ROS in android. I know I should transport it by the cv_bridge, and I had import the OpenCV-for-Android package in my Android Studio. However, I don't know how to make a local image transformed into CvImage by OpenCV, and finally make it to sensor_msgs.Image/CompressedImage messages. Do you have a good suggestion to make this possible?

My idea is something like this:

        filePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString() + "xxx.jpg";
        try {
            fileInputStream = new FileInputStream(filePath);
        }
        catch (IOException e) {
            e.printStackTrace();
        }

        bmp = BitmapFactory.decodeStream(fileInputStream);

        // compress
        byteArrayOutputStream = new ByteArrayOutputStream();
        bmp.compress(Bitmap.CompressFormat.JPEG, 200, byteArrayOutputStream);

        int quality = 200;
        while (byteArrayOutputStream.toByteArray().length / 1024 > 200) {
            byteArrayOutputStream.reset();
            bmp.compress(Bitmap.CompressFormat.JPEG, quality, byteArrayOutputStream);
            quality -= 10;
        }

        byteArrayInputStream = new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
        bmp = BitmapFactory.decodeStream(byteArrayInputStream, null, null);
        channelBufferOutputStream.buffer().writeBytes(byteArrayOutputStream.toByteArray());

        // bmp to mat
        mat_image = new Mat();
        Bitmap copyBmp = bmp.copy(Bitmap.Config.ARGB_8888, false);
        Utils.bitmapToMat(copyBmp, mat_image);

What about the next to deal with the mat_image (or other way) ?