Blog Post
Delta Sigma Converters: Modulation
The web is filled with introductions to Delta Sigma modulation (also sometimes referred to as Sigma Delta modulation) in the context of Delta Sigma converters. Unfortunately, the ones I’ve looked at fail to intuitively motivate how the modulator works. Therefore, my goal in this post is to show how the structure of a first-order ΔΣ… View Article
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The Math Behind Analog Video Resolution
The world is moving in the direction of HDTV, but NTSC “standard def” signals are still common for many reasons and will remain so. One important reason is that cameras that output NTSC are widely available and cheap! Many applications, including a lot of security applications, simply don’t require the resolution of HDTV — and… View Article
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Blog Post
Noise Floor
As shown in a previous post, for samples taken from a zero mean i.i.d noise signal, the expected power of the k’th DFT coefficient is given by As discussed in that post, when plotting the power of the k’th coefficient as a function of frequency, the “noise floor” will decrease as N increases… View Article
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Uploading Kodak Zi8 Videos to Flickr
Recently my mom bought me a Kodak Zi8 pocket HD video camera for my birthday. Thanks, Mom! You know what an engineer likes! I love photography, and I upload my photos to the Flickr photo-sharing site. But I think my mom wanted some more home movies of my daughter. The first day I had it,… View Article
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Working With CUDA
We’ve recently been working with a cool technology that is rapidly penetrating scientific and engineering computing, but seems little known otherwise. It’s called CUDA. In a nutshell, it is an SDK to allow you to run parallelizable compute-intensive applications on your Nvidia graphics card instead of serially on your CPU. CUDA is one of a… View Article
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The Importance of Encrypting Video Over IP
I just read a report of a new IP security vulnerability being demonstrated today at the DefCon hacker’s conference in Las Vegas. The new hack has two components:
1. The attackers are able to view video being streamed across a network, and
2. The attackers are able to use a man-in-the-middle attack to insert video controlled by the attacker to a video decoder somewhere on the network.
The linked video shows viscerally how an attacker could foil a security/surveillance video system — a modern-day Thomas Crown Affair.
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