Infra-Red/UV Video Image

Segmentation Technique Theory

Mickael Maddison, May 2010

Currently the movie and photography industries utilize techniques often referred to as “chroma-key”, “luma-key” or “thermo-key” to film subjects for the purpose of removing the subject from the background of the image. Once the subject is removed from the background of the image, the subject can then be superimposed on alternative backgrounds. For example, filming an actor in front of a “green screen” and using the chroma-key technique to remove the actor from the green background would allow the video editor to place the actor on an image of the moon; without ever having to go to the moon.

Existing techniques for image segmentation require very careful and often expensive settings, lighting and filming techniques in addition to powerful post-production processing to achieve a quality result. This document proposes the use of the Near-infrared spectrum and optional ambient UV to replace the background; allowing for a much simpler means of extracting the desired image from an infrared background. Using a selection of isolated IR wavelengths and CCD or CMOS digital camera technologies adapted to capture and record these isolated wavelengths while at the same time recording the standard RGB (Red Green Blue) or RGBY (Red Green Blue Yellow) visible light would allow for software and devices to be produced will allow subject(s) to be removed from backgrounds with a higher degree of accuracy while requiring far less effort and processing.

* Adding in the detection of UV spectrum will also allow for additional processing options.

Uses: Cameras equipped with combined RGB/RGBY and IR/UV CMOS or CCD sensors would have a wide variety of uses.

• Standard Video capture and recording.
• Image Segmentation.
• Capturing and recording Near-infrared and UV used for special effects/artistic purposes.
• Capturing a wide range of light spectrum useful for night-vision image capture.
• Reconnaissance and security systems.
• Scientific research requiring combined access to visible and non-visible spectrum images.
• Other techniques and uses not yet considered or developed.

Technologies:

1 – CCD: Existing CCD and CMOS sensors already have the capability to record near-infrared wavelengths. Most cameras use a special filter to block the infrared wavelengths from being captured. Cameras that do not have this filter in place store the infrared information in the RGB image. Currently, CCD and CMOS type sensors capture RGB light by using a special “Bayer Color Filter” as seen here:

Each square represents one “pixel” of information captured by the sensor. Processing techniques may vary, but in effect a square of 4 pixels are combined to create a single pixel of “true” color.

The following is an example of how a new filter could be designed to allow for the capture of the additional non-visible spectrum using the existing sensors:

In this sample image, instead of using a pattern of 4 pixels, the pattern is spread over 9 pixels. The 4 existing RGB pixels are captured in addition to 5 additional pixels as represented by the white and various shades of grey boxes. The optimal configuration is subject to analysis, but for example it could be laid out like this:

Red = Red, Blue = Blue, Green1/2 = Green1/2
White = wide-spectrum UV
lightest grey = 840nm IR, second-lightest grey = 900nm IR
third-lightest grey = 950nm, darkest grey = 1000nm OR wide-spectrum IR.

As a future consideration, there are also technologies coming that could utilize the optical properties of carbon nanotubes to capture information on specific wavelengths. Research has shown that a single carbon nanotube connected to a pair of electrodes can can measure IR radiation effectively. This technology may be a long way from practical use, however, it provides an ongoing opportunity to continue developing and refining the technology.

2 – File Format: In addition to the filter, a new image/video file format would be created to store the captured information in a useful format. Many cameras have built-in processors that convert the RAW pixel data from the CCD into consumer file formats such as mpeg, jpeg, tiff, etc. A new processor may be developed to provide traditional file formats + a masking file, or for more advanced use the camera may save all the data together to allow for more advanced processing and usage of the recorded data.

The new image/video RAW format would have more information available and would need to store unique information for each displayed pixel to be effective for image external processing.

3 - Software: Image and video editing software would require modifications and/or filters to be developed that would make full use of the extended information available through the new file format and/or the processing of the masking file with the video file. This may be modifications and additions to versions of existing industry-standard software. In addition, research may deem entirely new software should be developed to make full and wider ranging use of the data.

Some image processing systems have experimented using non-visible light to increase the accuracy and quality of the visibly produced image. For the purpose of image segmentation, the various wavelengths of non-visible light would be used to create highly detailed “mask(s)” useful for cropping the background from the desired image(s).

4 - Non-Visible Illumination: To make the most of the technology, a wide range of electronic devices would be developed as the technology is adopted by the relevant industries. Some examples of devices that would be developed and produced:

• IR floodlights – wavelength specific floodlights to provide a suitable non-visible background.
• IR spotlights – wavelength specific spotlights that could be used to segment multiple objects within a single image by using multiple wavelengths.
• IR backdrops – currently most greenscreen type applications use light shining evenly onto a controlled, smooth surface. An IR backdrop could be a “screen” that actually emits the light from it’s surface.
• IR/RGB backdrops – Using modifications of technologies that are hitting the market today, large LCD screens using LED backlight technology could be redeveloped to emit a combination of visible and non-visible light, allowing a for a fully visible background while at the same time providing the non-visible background needed for image segmentation.
• IR absorbing and reflecting materials – these could be used to achieve a variety of effects. For example, the current industry uses chroma-suits to allow the segmentation of parts of a subject such as a body-less person.

Benefits of the Technology

• Subjects could be photographed or filmed against a variety of backgrounds and still be easily removed from the scene.
• Subjects could be filmed with against a background that has similar colors and textures to the scene they would be placed into. For example, an actor could be filmed against a projection of a mountain scene similar to the one that will be added during post production. This would allow for complex images such as hair to more easily be segmented with minimal artifacts.
• A single background could be used for full color filming, even if the background color matches the color of subjects being segmented from the scene.
• Shadows appearing on the background may have little or no effect on the IR mask, allowing lighting of the subject to be tailored to the final scene rather than to achieving the best separation of color from the green screen.
• Artistic photography, such as family portraits, would be able to eliminate the need to have a wide variety of backgrounds available to photograph subjects against. Instead, the photographer would use a generic or projected image as the background. After (or during) the photography session, the photographer could select the actual background image from an unlimited selection of background images. This allows the photographer to use a single quality photograph for any number of scenes.

Patent and related technology research:

Live Action Compositing example http://www.scribd.com/doc/654481/Live-Action-Compositing

Using human-IR heat for image segmentation http://nae-lab.org/project/thermo-key/

Patents:

http://ip.com/patapp/US20060066738

http://www.google.com/patents/about?id=4TwGAAAAEBAJ&dq=6198503

http://www.google.com/patents/about?id=-iEzAAAAEBAJ&dq=6198503

http://www.google.com/patents/about?id=ij8dAAAAEBAJ&dq=6198503

http://www.google.com/patents/about?id=TPgfAAAAEBAJ&dq=6198503

This is not for IR - it is a device that uses a mapped background

http://www.google.com/patents/about?id=deMbAAAAEBAJ&dq=6198503

http://www.google.com/patents/about?id=9NUWAAAAEBAJ&dq=6198503

References:

http://www.computer.org/portal/web/csdl/doi/10.1109/MCG.2004.10009

Practical Example of Theory

Apparatus

Sony DCR DVD203 Digital Camcorder used in photograph mode.

Stable Tripod.

IR narrow-beam floodlight (wide beam would be much more effective)

Blue floor mat for background

Doll with hair

A Dark room

Computer system with Adobe Photoshop Elements 8.0

Methodology

Step 1 - photograph still image of subject in Nightshot plus mode which uses NIR to enhance image visibility.

Step 2 - photograph still image of subject in normal RGB mode (sorry for poor quality photo).

Step 3 - Open these to images into a single layered file in Photoshop (elements)

Step 4 - On the nightshot (Mask) layer, convert to B/W and increase contrast and in this case, with a blue background used, I adjust the blue level to get the best differential I can considering the poor lighting. You can see in this step that the segmentation opportunity is pretty good but not nearly perfect. The beam from the IR spotlight is a little too intense and focused. Developing proper Infra-Red lighting would not be difficult, at least in this scene.

Step 5 - Due to inadequate lighting I will cut excess dark regions (which would normally appear as a fairly even white background with proper IR lighting) and delete to pure white to match the area around the subject. As part of this step I have increased the contrast to show clearly the mask that was created. Proper lighting and some minor filtering would remove the manual portions of this step making it easy to automate.

Step 6 - Using magic wand (which would be an automated part of the process) I select all the white area and invert the selection to have the mask selected.

Step 7 - switch to the layer with the RGB image and copy the subject and paste into a new layer.

Step 8 - Turn off the visibility on all layers except the cutout of the subject. You now have a fairly good cutout of the subject to work with.

Step 9 - Insert background and adjust cutout layer as desired.

Notes

Due to nightshot plus mode captures IR data and incorporates this into an RGB image. Due to this, the Mask layer is not nearly as good quality as if an actual IR layer were saved in addition to the RGB layer. This limitation also requires the Mask layer of the subject to be shot in (visible) darkness to generate a strong contrast. The RGB layer is then shot in RGB mode with visible lights enabled. If I had 2 nightshot cameras of the same type, split the image into the 2 cameras, and had a filter on the RGB mode camera to remove all IR data and a filter on the nightshot mode camera to remove all RGB data I believe I would get a much more accurate mask.

For example, in unedited images you can see that the hair sticking up off the head is visible. With even IR lighting and no conflicting RGB data being stored on the mask layer, this should result in an even sharper, more accurate mask layer. The sharper, more accurate mask layer could then be used to cut out these fine details from the RGB subject layer, providing a nice crisp image to work with.

Also of note based on previous experience doing still-frame image compositing the process outlined in this document was very quick and simple to do. With proper camera(s), proper lighting, suitable software, and a good studio environment the results should be far better than this simple test.

It’s been awhile since I’ve been back stomping around Vancouver Island… Check this out… this Sunday evening at 6pm the Nanaimo station, CHWF 1069 The Wolf is featuring Sweet Misery during Fresh Tracks. Fresh Tracks is their Sunday night feature show, showcasing six new singles every week. On Sunday the 11th you can hear Sweet Misery smack dab between Kings of Leon and Theory of a Deadman!

I’d like to shout out to Music Director Jaimie Hilts for taking the time to listen to the new CD and spin this track on her great station. Who knows, maybe if you email her at jhilts@islandradio.bc.ca and let her know how much you’ve enjoyed the new CD - perhaps The Wolf will continue to play the track?

Thanks everyone for all your great support… Stay tuned… I’ve got some news about the live band coming out soon!

Mickael Maddison

Building on the successes of his debut EP “Free“, Mickael Maddison is releasing his emotionally charged 10 song album “In Loving Misery“; both a wide-angle lense into his life and relationships, and a tribute to the memory of his father. “…having previewed a few tracks myself I can already attest to the evolution of Mickael Maddison. The concepts and musicality of songs like Forward Today and Sweet Misery evoke sweet emotion…” Ara Andonian - Off Centre Magazine

Mickael’s fusion of hard rock, Seattle grunge and coffee shop singer/songwriting gives “In Loving Misery” a strong flavor that makes him stand out from the crowd. Mickael explores his diverse talents, laying down his own drums, bass and lead guitar for various songs throughout the album. His release features contributions from performing bandmates, Jonathan Anthony (Bass) and Doug McCallum (Drums), as well as artists Phil Maloney, Dan Hum and James Lipoth.

The release is expected to gain radio and media support and will be available through HMV music stores, at online stores including CDBaby.com (USA/Int.) and indiepool.com (Canada), and also for download on iTunes and most major online music providers.

Remember how sweet it was when GnR came out with Appetite for Destruction?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like GnR.

Remember how crazy the world was when Megadeth launched Symphony of Destruction?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like Megadeth.

Remember how stunned the world was when Motley Crue was spewing out their Dr. Feelgood cassette?
Now click on my profile pic and take a deep breath full of Molecules of Oxygen.
This track sounds nothing like the Crue.

Remember how Pantera left the world cold as steel with their metal chops?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like Pantera.

Remember how Cory Hart darkened our vision when we all started wearing sunglasses at night?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like The boy in the box.

Remember how Alice Cooper bit the heads of chickens and drank their blood?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like Alice Cooper.

Remember the time when Twisted Sister was running around causing dissent?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like “We’re not gonna take it". Seriously.

Remember the times when Def Leppard was pouring their sugar on everybody?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like Pyromania or Photograph.

Hey guys… what’s happening?
Remember how Fear Factory thrashed the world with Demanufacture?
Now take a deep breath full of Molecules of Oxygen.

This track sounds nothing like Edgecrusher. It’s also not Obsolete.
Remember when GnR had an Appetite for Destruction?
Now take a deep breath full of Molecules of Oxygen.
This track sounds nothing like Paradise City.

I’m just bleeding out of the gills today. I’ve posted “Molecules of Oxygen” (click to listen) up at MySpace so all the fanatics out there can check out another of the tracks coming up as we near the completion of my second CD - my first 10 song Album!

The guitars are twitchy, the bass is growly , they lyrics are a little odd and hey, some sushi would be nice right now.

Click above and breath “Molecules of Oxygen” deep into your lungs. For dessert, try a little “Sweet Misery” pie.

Mickael Maddison

UCE Protect provides ISP’s, Hosting Providers, businesses and individuals around the world with a simple tool that helps significantly reduce the amount of spam that a mailserver ends up processing on a daily basis. For one server I manage, I see over 185,000 blocked messages thanks to their service.

Other DNS blacklists such as “Spamcop” and “Spamhaus” contribute additional results bringing the total blocked messages into the 200,000+ range, or one day! Imagine, over 6 million message blocked per month by these services.

Normally, if an ISP gets listed on a significant blacklist they would take quick action to track and resolve the issue, then contact the blacklist they’ve been listed with for removal information. It appears that Bell/Sympatico have not taken up this cause at this time, as the complaints continue to trickle in, and their IP address(es) continue to be blocked (see
http://www.uceprotect.net/en/rblcheck.php to check your mailservers IP - or better yet, get your ISP to review)

UCE Protect’s policy on listing IP addresses can be reviewed on their website.

It seems I’m not the only one hearing the complaints:
http://www.littlereport.com/node/78

Anyway, here’s hoping they’ll take action soon. I’m sure they have a lot of clients that would prefer to have their mail sending work more often…

So I’m officially up to 7 songs finished up for the next CD. Hoping to get a few tracks laid out before I call it an LP. Anyway, have a visit to my MySpace page HERE and listen to one of the new tracks “Sweet Misery"… we had a lot of fun putting that one together.

Mickael Maddison
www.myspace.com/mickaelmaddison