News: Tips and tricks: recursive show images

The "Mastering OpenCV with Practical Computer Vision Projects" book is done and published!
Also: including a screenshot of each project...
This will be the main issue.
... to see the screenshot from each project
...and also to find a way for any file to use
Let's take the book and source code:

$ git clone git://github.com/MasteringOpenCV/code.git

Go to the main folder: $ cd code and use this:

code]$ ls 
Chapter1_AndroidCartoonifier     Chapter7_HeadPoseEstimation
Chapter2_iPhoneAR                Chapter8_FaceRecognition
Chapter3_MarkerlessAR            Chapter9_FluidInteractionUsingKinect
Chapter4_StructureFromMotion     LICENSE.txt
Chapter5_NumberPlateRecognition  README.md
Chapter6_NonRigidFaceTracking

If we use the tree Linux command the result will be:

.
|-- Chapter1_AndroidCartoonifier
|   |-- Cartoonifier_Android
|   |   |-- AndroidManifest.xml
|   |   |-- jni
|   |   |   |-- Android.mk
|   |   |   |-- Application.mk
|   |   |   `-- jni_part.cpp
|   |   |-- project.properties
|   |   |-- res
|   |   |   |-- drawable
|   |   |   |   `-- icon.png
|   |   |   `-- values
|   |   |       `-- strings.xml
|   |   `-- src
|   |       `-- com
|   |           `-- Cartoonifier
|   |               |-- CartoonifierApp.java
|   |               |-- CartoonifierView.java
|   |               `-- CartoonifierViewBase.java
|   |-- Cartoonifier_Desktop
|   |   |-- CMakeLists.txt
|   |   |-- ImageUtils.h
|   |   |-- ImageUtils_0.7.cpp
|   |   |-- cartoon.cpp
|   |   |-- cartoon.h
|   |   `-- main_desktop.cpp
|   |-- README.txt
|   `-- screenshot.png
|-- Chapter2_iPhoneAR

We need something to find the absolute path and give that to gthumb to run it.
First, find the screenshot:

 code]$ ls -d  $PWD/**/*.png
/home/free-tutorials/code/Chapter1_AndroidCartoonifier/screenshot.png
/home/free-tutorials/code/Chapter2_iPhoneAR/screenshot.png
/home/free-tutorials/code/Chapter3_MarkerlessAR/screenshot.png
/home/free-tutorials/code/Chapter4_StructureFromMotion/screenshot.png
/home/free-tutorials/code/Chapter5_NumberPlateRecognition/screenshot.png
/home/free-tutorials/code/Chapter6_NonRigidFaceTracking/screenshot.png
/home/free-tutorials/code/Chapter7_HeadPoseEstimation/screenshot.png
/home/free-tutorials/code/Chapter8_FaceRecognition/screenshot.png
/home/free-tutorials/code/Chapter9_FluidInteractionUsingKinect/screenshot.png

Now will run gthumb with all these images:

code]$ ls -d  $PWD/**/*.png | xargs gthumb 

News: Tips and tricks: watch and cat.

Sometimes it is necessary to find solutions.
Today's example involves two Linux commands:
watch and cat
Here is a simple method by creating a script that returns an output:

while [ 1 ]; do cat /proc/meminfo; date; echo; sleep 1; done

Make this script executable and name it: meminfo.
The output is then processed by the command:

$ watch -d ./meminfo 

This simple method can be applied to other files ...

News: About light laptop with your Linux distros.

ZaReason is launching a thin and light laptop called the UltraLap 430.
Linux computer builder has all the specs you’d expect from a modern ultrabook.
Prices start at $899 and it's available now from the ZaReason store.

Features:

• 14.1" HD (1366x768) Glossy LED Backlit Display
• 3rd Generation Intel Core Processor
• Intel HD 4000 Graphics
• Quick performance and power-on times with Solid State Disks
• HD Stereo Speakers
• 802.11 B/G/N WiFi included
• Bluetooth
• 3 in-1 card reader -- SD/MMC/MS supported
• 1.3 Megapixel HD webcam included
• Multi-gesture touchpad

Ports:

• HDMI port
• Gigabit Ethernet port
• Kensington lock port
• Headphone/Mic Jack
• 2 USB 3.0 ports
• 1 USB 2.0 port

Specs:

• Your choice of a variety of Open Source operating systems, like Fedora 17
• Battery Life: Up to 6 hrs
• Dimensions (WxDxH): 13.5in x 9.25in x .75in
• Weight: ~3.5 lbs

OpenGL Driver support for Linux and Windows.

NVIDIA has released a set of OpenGL 4.3 drivers for Windows and for Linux.
The driver support provides beta support for OpenGL 4.3 and GLSL 4.30 on capable hardware.
For Linux, the version number R304.15 is not the same with the drivers for Windows: R305.53.
All ARB extension specifications can be downloaded here: this page.
For OpenGL 4 capable hardware, these new extensions are provided: ARB_compute_shader ,ARB_multi_draw_indirect ,ARB_shader_image_size ,ARB_shader_storage_buffer_object
You can download all drivers from here.

Testing your disks using dd utility and time.

You can execute copies a large block of data to and from disk.

This will minimize disk caching.

Next is one example if our test system has 1GB of RAM.

It is easy ( 1GB = 250,000 blocks ).

$ time sh -c "dd if=/dev/zero of=bigfile bs=8k count=250000 && sync"
250000+0 records in
250000+0 records out
2048000000 bytes (2.0 GB) copied, 37.0113 s, 55.3 MB/s

real 0m40.910s
user 0m0.172s
sys 0m12.641s

It's very hard to argue with this dd test.