However, if this issue is too much of an eye-sore for you too, there’s a simple way to remove this, as detailed in this archlinux blog.The change in appearance is best represented by the below screenshots.
This is the thing I truly love about Linux distros.. if you dont like something, just change it as per your wish! 🙂
Thanks to excellent explanation provided at this xda link, kernel build was almost a cakewalk!
Kernel build produces a zImage, which is a compressed image of the kernel. Next step involves packaging the kernel into a form that a custom recovery installed in your Android devices can read it (FYI, I am currently using CWM Recovery).
Kernel packaging involves the following steps:
Extract ramdisk (or, initramfs on older devices) from an existing boot.img. This can be obtained from freely downloadable flashable kernel zips corresponding to one’s device.
Use this ramdisk along with the built zImage to create a new boot.img
Create a zip out of this boot.img and META-INF folder that was obtained from flashable kernel zip in 1).
The linux tools for performing the above can be obtained from this link.
Once the zip is ready, copy it to your sdcard, boot to recovery and select option : install from zip and select your flashable kernel file.
Finally, a screenshot from my device 🙂
Screenshot of new kernel install
A major problem am facing presently is that WiFi on this device is not working since the new kernel install. Will try to figure out the issue and post an update soon.
The Image Processing Toolbox in MATLAB has this very useful utility called as ginput, which allows manually picking co-ordinate points from an image. I tried to recreate that functionality in python based OpenCV, and the result is the following code:
import numpy as np
from matplotlib import pyplot as plt
a = np.array([0,0], dtype='float32')
DEBUG = 1
print "Using OpenCV version : ",cv2.__version__
print "TASK : Mimic getxy() feature of MATLAB"
#print "For verbose mode, set DEBUG flag"
DEBUG = 0
#define the event
def getxy(event, x, y, flags, param):
if event == cv2.EVENT_LBUTTONDOWN :
a = np.vstack([a, np.hstack([x,y])])
print "(row, col) = ", (x,y)
#Read the image
img = cv2.imread(imgPath)
print "Reading the image..."
#Set mouse CallBack event
print "Set MouseCallback functionality..."
#show the image
print "Click to select a point OR press ANY KEY to continue..."
#obtain the matrix of the selected points
b = a[1:,:]
print "The clicked points..."
print b, b.dtype, b.shape
print "The selected points are returned as a float64 MATRIX..."
Steps to use it :
save the above source code as getXY.py in your working directory.
In your python code, import this file, i.e.,
from getXY import *
Pass the image path to getXY, and start clicking on the displayed image. The no. of times you click, those many points will get saved.
If you want a verbose version, set the environment variable DEBUG = 1 from the terminal before running the code, i.e.,
DEBUG=1; export $DEBUG
That’s it! I’ll upload the code onto a git repo as well soon and provide a link here as well.
To remove the verbose code, unset the DEBUG variable, i.e, :
For the next few months, we shall concentrate on AOSP, both the application framework and its internals. We shall also see integration of OpenCV applications into the AOSP framework, and explore the power that a Linux device gives to its owner.
Once we leave the haloed portals of our alma mater, accessing the internet ceases to be a luxury it once used to be. Keeping an eye on network bandwidth usage in order to stay within data pack limits becomes utmost important. In such a scenario, a simple and extremely elegant command line tool called vnstat comes to our rescue.
To begin using vnstat, install it:
$ sudo yum install vnstat
Now, we need to tell vnstat which interface to monitor. First check the list of interfaces available on your system:
$ ip link show
This will print something like the following :
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: p2p1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT qlen 1000
link/ether 00:16:d3:26:73:dc brd ff:ff:ff:ff:ff:ff
3: wlp3s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether 00:16:cf:18:57:6c brd ff:ff:ff:ff:ff:ff
4: wwp0s29f7u2i1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether 58:2c:80:13:92:63 brd ff:ff:ff:ff:ff:ff
5: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN mode DEFAULT qlen 3
On my system, am interested in the mobile broadband connection (ppp0). Hence, we point vnstat to monitor it :
$ sudo vnstat -u -i ppp0
Now, make vnstat daemon auto start at boot :
$ sudo systemctl enable vnstat.service
Unfortunately, vnstat log file gets created as a root and not as a normal user. Hence, we need to change its permissions to allow vnstat to write data to it. This step will remove the frustrating
ppp0: Not enough data available yet.
issue. Simple type the following to change owner and group:
There were days when we had to painstakingly go through the manual install process for getting OpenCV running on our systems. Those days are long gone, and for the good. Current day distros bundle both OpenCV and ffmpeg in their repositories, making life extremely easy for enthusiasts and geeks alike. The following 4 steps provide a fully functional OpenCV install on Fedora:
That’s it! Dont believe me, well run a sample python or c code and see for yourself! 🙂 You can download this PDF file containing a sample code written in both python and C. Provide the video file appropriately and enjoy seeing your OpenCV installation playing a video file.
For e.g., if we need to run freenect-glcview, that comes bundled with libfreeenct library, we need to execute it as:
fakenect <path_to_data_folder> freenect-glcview
and we’ll get access to the pre-recorded data as though an actual Kinect device was connected! Now comes the interesting part.. How to record such a data? We could do it using freenect-record that comes bundled with libfreenect, but it doesnt let the user know what is being captured due to absence of any GUI.
kinect_record is a nice little code meant to record and show what is being recorded simultaneously. However, compiling this little gem needs some tweaking to the Makefile.linux that comes bundled along:
This should be enough in most of the cases. I hit an additional error message: undefined reference to symbol ‘pthread_key_delete GLIBC_2.2.5’. This was resolved using this suggestion and the corresponding edit to LDFLAGS variable makes it look like: