You can make a seemingly innocuous portrait come to life using an ornately framed flat panel TV powered by a Raspberry Pi. With proper lighting, it will look just like a painting, but every so often, the portrait subject's eyes will shift their gaze ever so slighting, sending chills up the spines of your unsuspecting victims, er, friends.

You'll use a hidden Raspberry Pi Zero as the image playback device to drive the TV over HDMI. Plus, you'll have a set of controls available using the buttons and thumbstick of the Joy Bonnet so you can pause and start the show, and more!

Parts and Materials

Most of the parts you'll need for the image player are provided in the Adabox 005 kit -- you'll just need to supply an OTG Ethernet hub or WiFi dongle, plus a keyboard and mouse. Here are the individual parts:

or

You can save some money and add some convenience by getting the Pi Zero budget pack instead of some of the individual parts above:

For the digital portrait you'll need:

• Flat panel TV with HDMI input
• Ornate frame, large enough to fit TV, or
• Framing material or crown molding (a cheaper alternative) to make your own
• VESA mounting hardware to hang the TV
• Miscellaneous hardware to affix the frame to the TV, such as small wood screws and angle brackets 

Tools

If you're going to cut a matte for your TV to fit a frame, you'll need a long straight edge or framing square, and a utility knife.

To cut a frame to exact dimensions or make one from framing or molding, you'll need a tape measure, hand saw and miter box, or a miter saw, as well as fasteners and wood glue, and some corner clamps.

Let's get started setting up the Pi Zero.

Pi Prep

First, prep the Raspberry Pi Zero so that you can attach the Joy Bonnet to it. You'll do this by attaching male headers to the Raspberry Pi Zero's GPIO pins. You have a couple of options here: you can solder on a standard 2x20-pin strip dual male header, or you can use the provided GPIO Hammer Header and jig.

To solder on the the standard pins, follow this guide.

If you don't want to solder on the headers, here's a great alternative!: Hammer Headers.

Hammer headers are special friction fit headers that include a little jig to hold everything in place, while you smash away at it with a hammer! OK, you may want to be a bit gentle with it, but not too gentle. You know, "hammer gentle".

OS Installation

SD Card

The Pi Zero can't do much without an operating system, so let's give it one. Insert the 8GB NOOBS (New Out of Box Software) micro-SD card into the Pi Zero's micro-SD card slot. NOOBS is an interface that makes it easy to install your operating system, in this case we'll install Raspbian Linux, once we get everything else plugged in.

Power

You can now power up the Pi. Make sure the TV is turned on, then plug the power supply into the wall, and the other end into the Pi's PWR micro-USB port. The green power indicator LED on the Pi Zero will light up, and then you'll see signs of life on the TV.

Install Raspbian

After your Pi Zero boots up, and you will use the NOOBS interface to install Raspbian. 

You'll want to choose the language and keyboard from the dropdown menus at the bottom (for example, English (US) and US), then check the Raspbian OS checkbox, then click "Install".

This is a great resource for more information on NOOBS and Raspbian installation. (Skip ahead to the section called "First Boot"), here are some highlights:

Congratulations, you've installed your operating system! 

Keyboard Layout

In case you didn't choose this during setup (I occasionally forget), now's a good time to adjust the internationalization of your system and keyboard to match your region. Here's a great guide on adjusting internationalization and keyboard layout, as well as some other useful configs.

Get Online

One nice feature of Linux is the ability to easily install software from online repositories by using simple commands. To access these, plug in an Ethernet cable from your local network router to the OTG hub on the Pi Zero. Alternately, you can use a USB WiFi dongle to get online. Here's a guide on setting up WiFi on the Pi.

Next, we'll set up the Pi Zero for image playback. This guide on building a Pi-based digital picture frame is an excellent resource, which I followed closely while building my Haunted Portrait.

I'll cover all of the crucial steps here, but you can head to the link for other details, such as setting up SSH, which we won't be doing here.

This file's parameters are read at system startup, so in order to invoke them, you must now restart the Pi Zero by typing: 

sudo reboot

in the Terminal window and then pressing return.

Once your Pi Zero reboots, we can move on to installing the image player software.

Now, let's install the image player!

You can now close the web browser.

NOTE: Another great way to get images onto your Pi Zero is by setting up the Pi as a Samba server. This allows it to be discovered on your network, and then you can drag files onto it from another machine! Here's a great guide to setting up Samba.

Install and Configure feh

Feh is a very nice command line image viewer, that happens to be perfect for running a slide show with specific parameters. It also allows key commands to be used while running, which is how we'll be able to use the Joy Bonnet to trigger different events.

Let's try out feh as a slide show viewer. Type this in the Terminal window (it may be easier to copy and paste it) and then press return:

 DISPLAY=:0.0 XAUTHORITY=/home/pi/.Xauthority /usr/bin/feh --quiet --preload --randomize --full-screen --hide-pointer --slideshow-delay 5.0 /home/pi/Documents/testPics &

One thing you can do to clean up your code is to use short versions of the option flag names, as seen here:

DISPLAY=:0.0 XAUTHORITY=/home/pi/.Xauthority /usr/bin/feh -q -p -F -Y -D 5.0 /home/pi/Pictures &

 This will do the same thing as the more verbose version above.

Close and save the shell script by pressing ctrl-x and then Y and return.

Now, run the shell script -- which will in turn run all of the contents of the file -- by typing this:

bash /home/pi/start-picture-frame.sh

That just ran your slideshow with a much shorter command. Much easier!

Now, we'll set up the Joy Bonnet to use as a slideshow controller.

Install the Joy Bonnet

The Joy Bonnet is a terrific little board! Originally designed to play video games in emulation, it's actually incredibly useful for adding a small set of controls to embedded projects as well.

Let's install the Joy Bonnet software so that the system can use it. You should already have the Joy Bonnet attached to the Pi Zero -- if not, do so now.

Installation is as simple as entering two lines in the Terminal, but you can read more details here in the Joy Bonnet Learn Guide.

Type this in to your Terminal to load the install script on your system:

Joy Bonnet Button Configuration

Now, we can set up the buttons on the Joy Bonnet to run particular commands for our slideshow by sending keystrokes to feh.

First, let's open the joy-bonnet.py script which contains the key bindings by typing:

sudo nano /boot/joy-bonnet.py

Scroll down to the section that starts with:

Then change the key assignments to the following:

Once edited, save the file by pressing ctrl-x followed by Y and return.

Reboot the Pi Zero so the changes take effect. Then, try out the Joy Bonnet buttons by opening a Terminal and pressing the buttons to "type" the assigned letters.

Now, let's use them as intended! Run the frame player script by typing this in your Terminal:

bash start-picture-frame.sh

Next, let's change the system to portrait orientation.

Rotate the Display

A large part of the visual impact of this project comes from hanging the TV vertically in portrait orientation. We're so used to seeing TVs in their horizontal landscape position, that the portrait orientation is novel and unexpected. This, plus the frame that we'll use, and careful lighting really sell the gag.

Now, you can save the file (ctrl-x, Yes, return) and then restart the Pi Zero by typing:

sudo reboot

Get ready to turn your neck sideways or rotate your monitor to continue! If you ever need to go back to regular orientation, change the config.txt file's display_rotate value to 0.

Autostart the feh Script

In the final Haunted Portrait, you won't have a keyboard or mouse connected (unless you use a wireless setup), so you'll want to set up the Pi Zero to automatically run your slideshow script on startup. This also means that if there is a loss of power, the system will not spend a long time stuck on a Linux screen!

To set the script to automatically run on startup, there are just two simple steps. First, we'll set the file permissions of the script to be "executable" by the system, not just the user who created it. Then, we'll add a line to the desktop environment configuration script that  automatically runs our picture frame shell script upon launch.

Permissions

Let's have a look at the current file permissions. In your Terminal, type this in to list the directory contents with verbose info:

ls -l /home/pi

That list of letters on the left side in front of each file shows you what type of permissions exist for the file.

Possible permissions are read, write, and execute for three types of accounts: owner, group, and user. Here's a very good primer on the subject.

For the slideshow script we see: 

-rw-r--r--

which means the file can be read and written by the owner ("root"), and only read (not executed or written) by groups and by users. This means the system (user "pi") doesn't have execution permission. So, we want to adjust that so the system can actually run the script without user intervention.

This simplest way to adjust this in our case is to grant execution permissions to all users. The chmod command is used to do so. Type this in your Terminal:

sudo chmod 755 /home/pi/start-picture-frame.sh

Now, list the file contents and you'll see the new permissions.

Autostart

Next, you will add a line to the desktop environment autostart file so it run the script after booting. Open the autostart file for editing by typing:

sudo nano ~/.config/lxsession/LXDE-pi/autostart

Add a new line at the bottom and enter this text:

@./start-picture-frame.sh

As is by now the familiar routine, save and exit the file with ctrl-x, Y, return.

Once again, you'll need to restart the Pi Zero to see the effects of your changes, so type: 

sudo reboot

When you tire of watching your test slideshow, you can press Esc on the keyboard, or the Select button on your Joy Bonnet to stop it. You can relaunch at any time by typing this into a Terminal window:

bash /home/pi/start-picture-frame.sh

Now, let's prepare some proper portrait images!

Now that your frame playback software is up and running, let's replace the test images with something more thematically appropriate.

How about Master Gracey, from the Haunted Mansion? This image was painted by character artist Corwin Webb, and is made available here with his permission. Thanks!

Check out  Corwin's illustration site for more excellent work! (I modified the painting in the second image to change Master G's gaze a bit, and to remove the pupils and irises in the third one.)

You can make modifications to any portrait in an image editor such as Photoshop or GIMP. One simple trick is to paint out the irises and pupils, leaving behind only a haunting set of scleras (sclerae?). 

Or, you can paint them entirely black. Creepy.

How about red eyes!

A slightly more advanced technique is to use an image deformer lattice or "puppet warp" in Photoshop to make the eyes squint or look in a slightly different direction.

Or, turn your own photographs into portraits using filters.

I took photographs of a family portrait, that of my great-great-grandfather, the Rev. William Park. I'm sure he was a very nice guy, but for some reason I think he makes for an excellent subject of a Haunted Portrait.

In order to amp up the spooky factor, I made a couple of copies of the portrait and modified his eyes so that his expressions change just enough to make viewers question their own eyes.

Here's the original.

In this one I image warped his eyes to change his gaze and expression slightly.

Finally, I repainted this image so his eyes are closed.

Now we're ready to frame the TV.

To finalize your Haunted Portrait, you'll want to place the TV inside an ornate picture frame, hang it from the wall, and adjust the lighting. Ideally, you'll also hide the wiring of the TV and Pi Zero power supplies by hanging the portrait over a wall outlet, or disguising the wires with a wall mount kit, color matched to the wall.

Framing

Here you can see one extreme -- where I removed the LCD panel and electronics from the plastic case and bezel in order to get the thinnest possible profile with a tight fit.

The fit was tight enough that I didn't need any fasteners to connect the frame to the LCD TV panel -- it simply stays on by friction, and the TV will bear the load when hung from the wall with it's built in VESA mounting points.

Attached the pre-existing power/input/volume button strip to the backside of the frame with double-stick foam tape.

I was also able to power the Pi Zero from the TV's built-in USB port, so one less power adapter to worry about hiding!

A less involved, but very attractive way to fit your TV to a frame is to buy a frame that is oversized and then cut (or have a framing store cut) a matte to match the TV screen dimensions. Or, how about an oval matte to further enhance the illusion?

Of course, portraits come in all sizes, so there's probably an old, small monitor kicking around somewhere in the back of your tech graveyard closet -- if you've got one with an HDMI input, why not turn it into a Haunted Portrait?!

Final Touches

Here are some thing you may be able do in your TV's control menus to maximize the quality of the effect:

• Turn off LCD backlight -- the less the image looks like it is transmissive light the better
• Adjust brightness and contrast  until the dark and bright portions of the image look realistic for a painting
• Turn off adaptive screen dimming
• Turn off automatic power down or screen saver

Tuning the Lighting

If you've seen digital portraits at theme parks, such as the living painting in the World of Harry Potter, there are a few things they've done that really make the effect work well. One of the most important is to control the lighting.

• You want to try to light the frame at the same level as is apparent in your digital portrait, and use small side lights to lift the frame without washing out the display
• At odds with this, you also want to avoid glare! Place the portrait in a place with limited viewing angles, such as the end of a short hallway
• Another trick is to use a matte finish screen if possible, or for the hardcore, even cover the screen in a thin level of thin, transparent gel medium or a matte film. Be careful, however: the matte effect work amazingly well when viewed straight on, but at oblique angles it can quickly reduce the amount of light visible from the screen and will go hazy gray
• Most of all, have fun figuring out the best ways to delight and spook your guests with your Haunted Portrait!

Another great spooky frame project to check out is this one on making a reactive, face tracking CG picture frame. Just in time for Halloween!