| Knowledge Base - Glossary of Terms |
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| Glossary is usually defined as an alphabetical list of technical terms in some specialized field of knowledge. This knowledge base glossary provides a collection of knowledge base documents that define many technical terms. These terms are arranged alphabetically, but you can quickly jump to a specific term by selecting its first letter from the index of the knowledge base glossary below. |
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| 296 Glossary Terms Found |
| Peak Height The largest peak measured from the bottom of the peak to the top of the peak. Peak Hold Averaging Each new FFT data point is compared with the current FFT data point, and the highest
amplitude (peaks) from each FFT are retained. This is a continuous operation that combines
the results of several measurements into a final FFT measurement. Peak Scaling The absolute value of the data from zero to the peak. Peripheral The input-output and storage devices attached to a computer such as disk drives, printers, keyboards, displays, data acquisition systems, etc. Phase Display Function Plots the frequency response phase shift (angle). PICT A standard for storing images that treats images as a collection of dots. Generally more efficient than the TIFF file format. PID Proportional, integral, derivative. A three-mode control algorithm. Pixel The fundamental picture element of digital image. Also, the coordinate used for defining the horizontal location of a pixel in an image. Pixel Jitter Pixel jitter is the variance in synchronization to the horizontal sync pulse. It subsequently results in mis-synchronization between the points at which the camera takes its pixel samples and the points at which the imaging board acquires samples. This mis-sync of sampling times results in the manifestation of image errors.
The image errors caused by pixel jitter are errors in the luminance level for a video signal that is varying across the length of the line. Let's say the true video signal is black on the left end of the line and white by the time you get to the right end of the line. Pixel jitter will make any given pixel a little more white or a little more black than it is supposed to be. Think of it as trying to sample pixel #n at 30 us but because of pixel jitter you end up taking your measurement at 30.006 us. That's farther to the right on the video signal, which is a little whiter than the point you were really trying to measure.
When the monitor paints the captured image out of memory, the pixel will show up whiter than it should.
You are most likely to observe the effects of pixel jitter on the borders of two contrasting colors or tones - like you get on a graybar test screen. The artifacts are observed at the border of the two tones as a fuzzines or blending of the colors. Pk-Pk Scaling The absolute value of the data from the negative peak to the positive peak. |
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