Howdy Pierce

The Cost of an Engineer-Hour

As all good project managers know, there are three dimensions to any engineering effort: The features of the product: What does the product do and how does it look? (For sake of simplicity, let’s include “quality” as a product feature.) The schedule on which the product is produced: How fast does it get to market?…

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Mike Perkins

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…

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Howdy Pierce

On the Importance of Encrypting Video

This morning brought a front-page Wall St. Journal article that’s a bit of a jaw-dropper: Militants in Iraq have used $26 off-the-shelf software to intercept live video feeds from U.S. Predator drones, potentially providing them with information they need to evade or monitor U.S. military operations. … The potential drone vulnerability lies in an unencrypted…

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Howdy Pierce

Outsourcing Just the 1.0

Seven years into running a services business, we’ve recently recognized a pattern across several of the projects we’ve done. The pattern is that the customer wants to outsource the initial development of a product but also wants to bring subsequent maintenance engineering and feature enhancement in-house. This pattern doesn’t apply to all customers or all…

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Detecting Well-Focused Images

Recently, one of my colleagues mentioned to me that he takes large numbers of pictures and wanted to write a program to automatically determine which was in the best focus, out of a group of pictures that were taken of the same scene. He mentioned that he expected the algorithm to be computationally intensive. My…

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Mike Perkins

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…

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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,…

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GCC’s Unhelpful Error Messages

Something must be done about the obtuse error messages issued by the GCC compiler, particularly when using C++ and STL classes. Take this, for example, which is the output I got recently after a one-line change: src/emmserver.cpp:739: error: conversion from ‘std::_Rb_tree_iterator<std::pair<const unsigned int, EMMServer::EMM> >’ to non-scalar type ‘std::_Rb_tree_iterator<std::pair<const unsigned int, std::map<short unsigned int, EMMServer::EMMSource,…

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Howdy Pierce

Why Do CDs Use a Sampling Rate of 44.1 kHz?

During a recent conference call discussing audio sampling rates, the question came up: Why do CDs use a sampling rate of 44.1 kHz? First, a little background: When you sample an audio waveform, you have a choice as to how many samples you take per second. Over the years, a number of standards have developed;…

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