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Posts Tagged ‘Mobile Video Evidence’

Tips for Mobile Video/Cell Phone Enhancement

Tuesday, January 20th, 2015

cell phone enhancementIn past blog posts, we have discussed techniques that we use as video forensic experts that get the best results when conducting CCTV video enhancement. What we have yet to discuss is how we get the best results when enhancing mobile video recordings.

Since most mobile video evidence is shot freehand on a smart-phone camera, you can’t guarantee that the video evidence will be of legitimate quality. People are often nervous when video recording something like a fight, accident or other public situation and naturally shake while recording. Smart- phone video quality is often good at best. The placement of your subject and method of recording video can lead to poor video evidence that needs forensic enhancement.

As a video forensic expert, we know firsthand about all of the tools available in software programs and out board digital signal processors that can help your video provide valuable information to the authorities.

At Primeau Forensics, we have a team of video experts that have reviewed and enhanced hundreds of videos, some of which are from smart-phone cameras. One of the most prevalent problems that we have noticed through experience is unstable smart-phone video recordings. The chaotic motion of a cell phone video can make it hard to tell what’s happening.

One of the tools we use is made by Adobe; Adobe products have excellent tools for video enhancement assignments. One tool can be found in Adobe After Effects. It’s a plug-in entitled the “warp stabilizer.” This plugin creates a full frame reference for the shakiness of a smart phone video. It enhances the viewer’s ability to view the video better and determine the events that occurred more effectively.

For example, we have posted two clips below. The first clip is from an actual video enhancement case. It was recorded using an iPhone. No stabilization has been applied to this video. Look at how difficult it is to see the events as they occurred.

IMG 1363 from Primeau Forensics on Vimeo.

In the next video, we take the same source clip, but this time apply several filters including warp stabilization. Notice how it is easier to view the video as the frame follows the motion of the video, creating a more stable picture for analysis.

IMG 1363.MOV CLARIFIED VIDEO from Primeau Forensics on Vimeo.

In many cases, such as the video above, the subject at hand will not be close enough to the smart-phone capturing the video, making it nearly impossible to make out the events as they occurred. In the first video example above, the subjects are very far away, making it difficult to make out what is happening.

A trained video forensic expert knows how to apply tools that will enhance the video evidence. These tools allow you to zoom in on a video and clarify difficult-to-see events. This process may lower your overall video quality, and as Hollywood may lead you to believe, fixing it isn’t nearly as simple as pushing the “enhance” button.

The reason that the quality of this video is reduced when zoomed in has to do with the video “pixels.”Simply put, pixels are the small boxes of color code that combine to make up a given image. Each image is composed of a specific amount of pixels that make up the clear image you see in front of you.

To further explain, think of a collage. Have you ever seen a collage composed of much smaller pictures? Once the pictures are combined in a specific order (usually by color), it creates a much bigger image. Think of pixels as those smaller square pictures that make up the entire picture.

Expanding an image also means increasing the size of each pixel. Because each pixel is a representative of one “frame” of a bigger picture, such as the photos making up a collage, each individual square pixel will expand along with the image. The increase of pixel size can cause distortion to the image, therefore making it even harder to decipher the contents of an image.

Luckily, Photoshop and other Adobe programs provide solutions called “pixel interpolation.”

Generally, pixel interpolation provides two options for this video enhancement situation. You can utilize a plugin known as the “bi-cubic smoother,” which blends each cubic pixel together to create a more cohesive image.

The other plugin is known as the “pyramid shaper.” This allows for a similar process, however, this follows what’s known as pyramid coordinates, an alternate method of morphing the pixels.

Which one of these methods is best comes down to the circumstances surrounding your investigation.

As you see in the second video, the image has been enhanced so the viewer can better see the events that occurred. It is important to note that the quality of the video hasn’t been compromised. This is because steps were taken like applying the bi-cubic smoother allowing the pixels to cooperate making a image more clear.

The biggest problem we see at Primeau Forensics with mobile video evidence is the orientation of the cell phone while recording.

If you should find yourself recording a video using a smart-phone, first and most importantly be sure to turn the phone on it’s side or ‘landscape’. We receive a lot of video evidence where the phone was held vertically instead of horizontally. This is fine when your intent is to view the footage directly on the phone, but when that footage becomes evidence; not having a full frame horizontal recorded video eliminates a large portion of the scene being video recorded. The vertical position records a much more narrow view of the scene and instead records larger height dimensions. This keeps potentially valuable information off the videos and out of the court room. It dramatically constricts the viewer’s range of sight of a given event.

Regarding the footage shown above; notice that around the 0:25 second mark, the camera focuses on the Jeep pulling up as another officer runs toward the scene. This distracts our focus away from the scene, and we miss a substantial amount of the incident.

Had this evidence been shot horizontally, we would have been able to view more of the events including the activity that happened as the officer arrived at the scene. We would also have been able to better see the white Jeep in the background which was an important detail.

Using another smart-phone video as another example, the footage below is a recording from a smart-phone of the events that transpired after this year’s tragic Charlie Hebdo shooting in Paris. The two gunmen are seen driving away from the scene of the crime before encountering a police car. The suspects shoot at the police car, causing the police to retreat, and speed off again.

If you notice, you’ll see two black bars along the outside of the vertical video. This video was also recorded holding the smart phone in a vertical position. Had this video been recorded holding the phone horizontally we would have more information recorded that may have revealed additional useful information. This scene happened just before the gunmen got away and killed additional people.

With the expansion of mobile video technology, any cell phone could effectively record a crime scene that can go on to become crucial evidence. The highest quality video recording can help litigators more effectively.

The Evolution of Mobile Video and What It Could Mean for Video Forensics

Thursday, September 4th, 2014

mobile video forensicsOver the past few years, we’ve seen a significant acceleration in the development and manufacture of consumer-grade, mobile video devices. From smartphones to GoPros, video recording has become substantially less expensive and far more accessible to consumers, and this may change the game regarding digital evidence.

This consumer video revolution now allows us to capture video of events as they occur. This phenomenon has created powerful repercussions in the courtroom. Thanks to the easy availability of video devices and trends in social media, we now have presented at trial video evidence of events that, until recently, have rarely been made known.

For example, take this video of a woman from Mississippi. As she begins to merge onto the highway, a truck hits her car, causing the car to catch fire. She seems trapped in the car (either physically, or due to shock), and with her children in the back and the flames coming ever closer to the gas tank, she needs to act quickly.

Suddenly, from behind the scene of the accident, another truck driver leaves his rig and tries to save the family by pulling them out of the burning car. Minutes after they are successfully rescued, the car explodes. Had the truck driver been a few minutes later, it is likely that the entire family would have been killed.

This is a heroic, inspiring story. An inspiring story that would have gone completely unnoticed if weren’t for the rescuer’s dash cam recording the entire incident. A heroic act so great that it has rarely been seen outside of movies and television, it became a huge story, and something that would have been unrecognized by the public without the technology of this generation.

However, the documentation of heroic stories like this is only the beginning of the positive effects from the spread of video devices to every pocket, purse, and vehicle. This public video revolution can also make or break a court case, providing the crucial evidence that makes true justice possible.

For this, let’s use the currently infamous video, “Officer Go-F***-Yourself.” The officer in Ferguson appeared at a peaceful protest late one night in August. He approached a group of young adult protesters with an assault weapon drawn, pointed it at them, and he told them that if they did not return to their homes, he would “f***ing kill” them.

In the world of law enforcement, this kind of behavior on the part of an officer is absolutely improper and illegal. The protest was peaceful; the young adults weren’t causing any harm or exhibiting disorderly behavior. Hell, even if they were, threatening protesters in such a crude manor is clearly unacceptable in a free society.

Had this happened 10 years ago, it might have gone completely unnoticed. The officer in question may have gotten away with blatantly making death threats to civilians, and the only evidence from the protesters would’ve turned into a game of “he said, she said.” However, because one of the protesters was smart enough to take out their cell phone and document the entire confrontation, justice was done and the officer was suspended from the force. The police in Ferguson were able to see the events exactly as they transpired, so it was indisputable that he was guilty. This, in itself, is revolutionary, and is an indication of how much power video evidence can have in the courtroom.

The fact stands that a clear representation, such as video, is the most indisputable evidence there is, and allowing the jury, officials and lawyers to witness the event with their own eyes and ears is the most effective way to present evidence. Other forms of evidence can be easily disputed, but allowing the court to see, hear, and experience the event for themselves is the most effective method of presenting evidence, even more reliable than an eyewitness account.

Think about it this way. Consider the most powerful documentaries you’ve ever seen. What do they all have in common? Generally, they all rely on the reality of the situation by allowing viewers to experience it for themselves. You can throw out as many facts and statistics as you want, but seeing, hearing, and experiencing actual issues, people, circumstances, and actions is what will stick with people most. The feeling viewers derive from seeing the faces and hearing the people speak is incomparable to any statistic in the world. This is why Charlie LeDuff’s piece on Ferguson is one of the most powerful, yet. It doesn’t focus on the narrative; it doesn’t focus on stats; it focuses on the people. It focuses on those who are so passionate about this cause that they would fight, risk arrest, or even die for it.

The consumer video device revolution is so important to the justice system, and the best way to reap its benefits is to remain aware of its power. If you experience anything unlawful, always remember that the little rectangle sitting in your pocket could make or break the fate of those guilty. These devices allow us to capture indisputable evidence about what truly took place, and this is a privilege we can’t ignore. If these developments continue, they could completely change the face of digital forensic evidence forever.

Mobile Surveillance Video Evidence Recovery – Hard Drive Cloning

Wednesday, March 26th, 2014

hard drive cloningMobile Video Evidence Recovery: Simple as Cloning the DVR’s Hard Drive?

With the rapid proliferation of surveillance cameras in public and private spaces, law enforcement agencies are increasingly making use of these recordings as evidentiary video at trial. Moreover, mobile digital video recorders and other portable video recording technologies are making it much more practical to capture surveillance/crime scene video that may latter be used as evidence in court. Playback of these video recordings is straightforward, providing the video is played back using the original equipment on which it was recorded.

This caveat, unbeknownst to many attorneys and police officers,stems from a simple fact.Most fixed and mobile DVR-based surveillance systems employ proprietary computer operating systems and record digital video to proprietary formats. Under these circumstances, causing minimal degradation of picture quality during the process of recovering and trans coding video files is a complex challenge for both law enforcement agencies and video forensic experts. There are a wide variety of surveillance system manufacturers and a larger number of different models of DVRs, which makes on-site retrieval of video recordings a difficult process, often necessitating access to the technical manual of the DVR on which the recording is stored.

The investigators at Primeau Forensics have worked on countless evidence recovery assignments where simple cloning of the DVR’s hard drive would have been the worst retrieval strategy of all. First, the cloned drive may not mount on our computers, which run Windows and Apple operating systems. Second, proprietary files are often invisible files outside their native OS. They cannot be detected or read by any operating system but the embedded OS running on the dedicated device. Third, video files may be encoded using a non-standard codec and/or formatted within a non-standard wrapper.

For example, NVR format video files, frequently used in surveillance systems, come in a multitude of types, each with its own structural and descriptive metadata. Associated files present, such as the control files and system files that enable playback on the original DVR, will often impede playback on general-purpose computers. File Investigator Engine and File Expander Engine from Dark Data Discovery allow forensic investigators to identify and open over 4,300 different types of files, yet simply cloning the DVR’s hard drive remains a strategy fraught with complications.

Successful retrieval of DVR recordings always requires preparation and research beforehand. We always browse the Internet, contact the manufacturer, and read the manuals over and over to determine the best way to preserve this fragile digital evidence in its most pristine quality. As trial verdicts may turn on the outcome of our analysis of evidentiary video, we want to personally recover the video to establish a clear chain of custody, prevent accidental loss of files, and preserve the video quality through recovery and trans coding to an open format.

We recommend the following 4-step process for retrieval of video from DVRs:

1)      As previously mentioned, research the design, inputs/outputs and operation of the DVR you are examining. Obtain the special software, codecs, and technical manuals necessary to examine the unit properly.

2)      Photograph the digital video recorder before you begin the inspection. Take note of any markings or signs of tampering.

3)      Connect the DVR or mobile digital video recorder to the power source that will power the unit best. Sometimes, mobile digital video recorders require an AC/DC cable system to power the unit in an office environment. The vehicle or locale in which it was originally installed may have had custom power connections, not available if the unit is pulled for examination.

4)      Connect the data transfer cable supplied with the unit to your Windows laptop for examination. In some cases, this will be a standard USB or FireWire cable. Mobile video recorders, in particular, frequently require a proprietary cable. Having installed the DVR emulation software provided by the manufacturer and the proprietary encoder/decoder, you are ready to follow the instructions in the manual to retrieve the highest quality video possible.

If you need professional assistance recovering video evidence from a digital video recorder, please call us today! Call 800-647-4281 for a free consultation.