Free Chroma Key - Green Screen / Blue Screen Photo Editing

Green Screen / Blue Screen - Chroma Key Photo Editing Tutorial

When you take a picture with a green screen or a blue screen background, some photo editors have a feature called "chroma key" to allow you to replace the green or blue color with any background picture of your choice.

The photo editor used here is Paint.NET with a free plugin enabling the chroma key / green screen - blue screen cabability.

The chroma key feature has adjustable sliders to fine tune the amount of blue or green that is keyed out.

To use this in a computer lab or a technology class, install and test the photo editing program and chroma key plugin in advance.

Have a good green screen background setup with good lighting, a selection of background pictures, and a camera ready to go.

Example: The "Before" pictures shows some people in front of a green screen background. The "After" pictures shows the results of using the chroma-key feature to remove the green background and put a vacation picture in it's place.

Things you will need:

1. Picture of yourself in front of a green screen background.

2. Paint.NET (A Free Windows application) (Download)

3. Free Green Screen / Chromakey plugin for Paint.net (Download)

Install Paint.NET.

Read the requirements, you may need to download an additional supporting program from Microsoft called the .Net Framework 3.5 SP1 (Free).  

Install the Green Screen- Blue Screen / ChromaKey Plugin

Once you download the ChromaKey plugin, unzip the file and copy the ChromaKeyPlugin.dll file  to the Effects folder of your Paint.NET program folder.

Here I've copied the plugin to the default Paint.NET program installation at  C:\Program Files\Paint.Net\Effects. If you had Paint.Net open, close it and restart it so it can find the plugin.

 

Place the following two pictures on your desktop:

Picture with a green screen background and a picture of your dream vacation location.
Open Paint.NET.

 

Drag and drop the VACATION picture onto the PAINT.NET canvas.

In the Drag and Drop dialog box choose "Add into layer(s)". Alternately, you add the picture from the menu bar: File > Open.

Here is the result. If needed, adjust the size of the vacation picture or the canvas size from "Image" on the toolbar.

 

Drag and drop your green screen picture onto Paint.NET canvas

Choose "Add into layer(s)" in the Drag and Drop dialog box. Alternately, you can add the picture from the menu bar: Layers > Import From File. 
On the menu bar choose Effects > Photo > Chroma Key.

 

Use the Chroma Key Slider to Remove the Green Screen Background Color

The ChromaKey dialog box offers sliders to adjust the amount of green color being keyed out. Adjust to suit your needs. Notice that there is an option to key out a blue background (blue screen).

Final result:

Green Screen - DONE.

Use these rules to keep your lab running smoothly throughout the year.

You can download the ready to print rules sheets or copy the rules you prefer to use on your own sheets.

I generally tell the children that the rules in the lab are the same rules that their regular teacher uses, but that I have a few of my own to add.

For the younger kids, (kinders) I don't usually go over the long list here, I juse use the Computer Lab Rules in the images version.

Computer Lab Rules - The Essentials in Pictures

  

Computer Lab Rules - Green

Computer Lab Rules - Pink and Blue

Computer Lab Rules Black and White

Computer Lab Rules Blue and Yellow

You can use this list to get ideas to create your own rules sheet.

Come in to the lab quietly and go to your assigned computer.
Do not touch other keyboards or mice on the way to your computer.
Read board & begin assignment if one exists or wait for instructions before you do anything.


Only visit approved Internet sites and only when you have permission to do so.
Do not download anything unless told to do so.
Never give out personal information.
Do not share your passwords with anyone other than your parents or teacher, if school related.
If you see anything that makes you feel uncomfortable, turn off your monitor and let your teacher know immediately. Do not show it to your friends first.


Make sure you leave your workspace as you found it!
Exit out of all programs. 
Hang up your headphones.
Straighten your keyboard & mouse.
Push in your chair.
Collect and throw away any trash on your way out.
Take your belongings and anything you have printed with you when you leave.


Print only if you have permission!
Only press the Print option once!


Use only your assigned computer.
Do not move the icons on the desktop.
Do not change any system settings without permission.
Do not edit files that do not belong to you.
Help others with your mouth and not their mouse.


Treat your classmates, your teacher & all equipment with respect.
Help your neighbors if they need help - with your mouth and not their mouse!

Do not talk when your teacher is talking.

Come to the computer lab with clean hands. If you have just had recess or lunch, please wash and dry your hands before you come to the lab.
No banging your mouse or banging the keys on your keyboard.
No hands on the monitors.

All four feet of your chair should be on the floor at all times.


Eat and drink OUTSIDE of the lab only.
No food or drink allowed in the lab!


Read the screen BEFORE asking questions.

---

Lights out means Your Attention Please.
Remove your headphones.
Take your hands off the keyboard and mouse.
Wait for instructions.


Ask your immediate neighbors for help before you raise your hand to ask your teacher.
Do not get out of your seat to ask for help.
Do not get out of your seat to help someone else.
If you help someone else do it with your mouth and not their mouse.


Be prepared to learn something new every day in Computer Lab.

Restore Windows 7 Disk Image from Backup Step by Step

Windows 7 provides a free and easy way to restore a complete installation from a backed up disk image.

Windows 7 disk images are restored using a system repair disc that can be created from a working Windows 7 installation.

To create your own system repair disc, go to Start > Control Panel > Backup and Restore > Create a system repair disc.

The restoral procedure and functionality is similar to more fully featured commercial programs such as Acronis True Image and Norton Ghost.

Step One:

Insert your Windows 7 system repair disc into the CD / DVD rom.

Start the computer and watch for screen that tells you to "Press any key to boot from from the CD / DVD." If you don't see that message, change the boot order to boot from the CD first in the BIOS.

If you haven't done this before, you can change your system's boot order in the BIOS.

To do this, restart your computer and before the splash screen displays press whichever key you are told. Might be F2, F1, F12 ? to enter Setup or BIOS.

In the Boot section you should then be able to adjust the settings labelled Boot Order, Boot Device Priority or another variation on this wording. Make sure that your CD/DVD drive is set to be your first boot device and you should be able to boot from a CD / DVD.

Step Two:

After the computer boots from the system repair disc, choose your language and keyboard input method.

Step Three:

In the System Recovery Options dialog box, select "Restore your computer using a system image that you created earlier".

Step Four:

In the Re-image your computer dialog box, choose "Select a system image".

Step Five:

If your backed up disk image is on an external USB device, plug it in now and click refresh. The system will start searching for and automatically show available images to restore.

Step Six:

If you have more than one system image to restore, choose the most recent one in this dialog box. In this example there is only one image to choose from.

Step Seven:

This box allows you to select some additional restore options. I have selected to Format and repartition disks here. This formats the destination disk to match the layout of the system image that is being restored.

Step Eight:

Review the restore settings and if they are correct, proceed with Re-imaging your computer.

DONE!!

Introduction to LCD TV Repair

Introduction to LCD TV Repair  

This month article is about the basic LCD TV repair. I do get emails from beginners asking about how to understand and troubleshoot LCD TVs. Although this is not a complete article about LCD TV repair, I believe this article in some ways could help them in understanding the main function of the important boards found in LCD TVs. Let’s start.

A-  Power Board 

B-   T-con Board 

C-   EMI Filter board (In other designs this board is built into the Power Board) 

D-  Inverter Board (In some designs this board is built into the Power board and is called as I/P board) 

E-   MainBoard 

F-    Jackpack 

G-  Side Key Panel/Power Control/Remote Receiver Unit (IR/LED control) 

H-  Left Speaker 

I-      Right Speaker 

J-     LCD panel 

K-  LVDS cable 

The function Of LCD TV section 

Power Board  

 

The Power Supply Board is usually the biggest and heaviest board found inside the LCD TV. Some repair techs call power supply board as “Power Supply Unit” and “Power Supply Module” or just “PSU”. It converts the main AC supply into DC voltages that can be used by the circuit within the LCD TV.  

Sometimes the power board is joined together with inverter board and is called as I/P board.

Common faults- No power, low power, power blink and intermittent no power. 

Timing Controller Board (T-con board) 

 

The T-Con Board is the smallest board found inside LCD TV and is usually only found in LCD TV's.  The function of T-con board is to control logic signal of gate and source for driving TFT LCD. The T-Con Board is sometimes referred to other names, such as "Controller Board," or "Control Board."  

A Typical T-con Circuit Board

Common faults- White Display, No display, Double image, Display distortion (black and white vertical bars on the screen). Multiple vertical/horizontal lines across the screen. 

Inverter board 

The inverter boards are usually found along the edges nearest to the TV Panel and are only found in LCD's. These boards function is to convert the low voltage DC supplied (12V or 24 V) by the SMPS into a high AC voltage (500 to 1500 Vrms) to light up the backlights. These boards can be found as a single board or built in with the power board called as I/P board. 

Common faults- Display shutdown after few seconds, Dim display 

Mainboard 

 

The simplest way to identify the Main Board is to look for the circuit board with the audio and video inputs and outputs.Sometimes the Mainboard is called as Motherboard, Main Unit, Digital board, Scaler board, A/V board, Main Module, Logic board or even A/D board. The function is to take in the video and audio signals and convert the analog video signals into digital signals that can be sent by the LVDS IC (low voltage differential signaling) to the T-con board.  

Note: Sometimes the audio section/RF Input/ Rear Inputs is separated from the mainboard. 

Common faults- No display, no color, screen full of vertical lines after sometimes, no sound, horizontal lines and block, sometimes the LCD TV fault (usually display problem) can be due to software problem where you need to update the software. 

Jackpack Section

 

The audio signal is taken to the audio processor and then audio amplifier which then drive the left and right speakers. 

Note: Sometimes the audio section/RF Input/Rear Inputs is separated from the mainboard (as seen from the above photo) and is called as Jackpack or Signals receiving board.

Common faults- No sound, distorted sound, High Pitched whine, no TV reception, unable to tune to certain blocks of channels, channels change randomly.

Below is the all in one Mainboard (Key Panel, Audio, RF input, Rear Inputs, Ram and Main MCU.

LCD Panel

LCD stands for liquid crystal display(LCD ) and it is a thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly thus backlights are needed to make these LCD displays visible.

Common Faults- Vertical/horizontal thin line/s or bar, white display, garbage display. 

Backlights (Lamps) 

 

The function of backlights (CCFL or EEFL) is to illuminate the LCD from the back of the display panel. 

Common faults-Display shutdown after few seconds and display flickering 

You can test the backlight by visiting my blog at :

how-to make a ‘usb battery’

  Hackaday

found out yesterday that there’s a shuffle shortage and gadget battery life can only be expected to get worse.  bummer.  at least you can make the most of your waiting-for-shuffle blues and solder yourself a ‘usb battery’.  this little gizmo runs off a 9 volt battery and supplies your favorite little device with the proper 5 volts of mobile power.
in lieu of running an ipod off of it, i tested it with an mpx220 smartphone and it should work fine with any low power mobile device that can charge via usb cable.  read more for instructions on how to make your own.


here’s what you need to scrounge up:

• 5.1v zener diode.
  
• 100ohm or slightly greater resistor.  all i had was a 330ohm which works.  don’t try anything lower than 100ohm.
  
• 9v battery connector and 9v battery.
  
• flat female usb connector that mates with your device’s usb cable.  this is the hardest part to find.  i tore mine off an old usb extension cable.
  

wire it up


connect everything up as shown.  a board makes it easy, but in a pinch you could just wrap ends together.  the top two wires go to the battery and the bottom two are connected to the female half of the usb cable i butchered.  polarity matters on the diode, so check your work.
test it

connect the battery and test the voltage over the diode.  it should be close to 5 volts.  if not, make sure you have everything wired correctly (pay special attention to the polarity of the diode).
try it

still waiting for an ipod, i decided to grab my smartphone and kick the tires on the usb battery.  as you can see in the image, the device thinks it’s plugged in.  you should be able to use any low power device that charges via usb.

how it works
the zener diode conducts in the reverse direction when its breakdown voltage of 5.1 volts is reached, and the voltage across the diode will be that same 5.1 volts, so it acts to limit our 9 volt supply down to roughly 5 volts, which is what usb powers devices at.
the resistor is there to keep the circuit from shorting when the load (your shuffle) is removed.  if you use a resistor less than 100 ohms you’ll know it because it will get hot.  if you use too large a resistor, you won’t be able to supply enough current to your device.
finish the job

as you can see, i’m pretty nasty at soldering.  i’m under strict orders from cl to keep this tiny and pocket sized for the ipod, so i’ve tried to cram everything as tight as possible.  as soon as minneapolis warms up enough for the ipods to migrate, i’ll be making a custom case for this.
till then, please send in your comments, ideas, and hacks.  i look forward to seeing what you come up with.