PQA600A Datasheet, PDF (3/19 Pages) List of Unclassifed Manufacturers – Picture Quality Analysis System

Picture Quality Analysis System — PQA600A
How It Works
The PQA600A takes two video files as inputs: a reference video sequence
and a compressed, impaired, or processed version of the reference.
First, the PQA600A performs a spatial and temporal alignment between
the two sequences, without the need for a calibration stripe embedded
within the video sequence. Then the PQA600A analyzes the quality of
the test video, using measurements based on the human vision system
and attention models, and then outputs quality measurements that are
highly correlated with subjective assessments. The results include overall
quality summary metrics, frame-by-frame measurement metrics, and an
impairment map for each frame. The PQA600A also provides traditional
picture quality measures such as PSNR (Peak Signal-to-Noise Ratio) as an
industry benchmark impairment diagnosis tool for measuring typical video
impairments and detecting artifacts.
Each reference video sequence and test clip can have different resolutions
and frame rates. This capability supports a variety of repurposing
applications such as format conversion, DVD authoring, IP broadcasting,
and semiconductor design. The PQA600A can also support measurement
clips with long sequence duration, allowing a video clip to be quantified for
picture quality through various conversion processes.
Prediction of Human Vision Perception
PQA600A measurements are developed from the human vision system
model and additional algorithms have been added to improve upon the
model used in the PQA200/300. This new extended technology allows
legacy PQR measurements for SD while enabling predictions of subjective
quality rating of video for a variety of video formats (HD, SD, CIF, etc.). It
takes into consideration different display types used to view the video (for
example, interlaced or progressive and CRT or LCD) and different viewing
conditions (for example, room lighting and viewing distance).
Picture Quality Analysis System
A model of the human vision system has been developed to predict the
response to light stimulus with respect to the following parameters:
Contrast including Supra-threshold
Mean Luminance
Spatial Frequency
Temporal Frequency
Angular Extent
Temporal Extent
Surround
Eccentricity
Orientation
Adaptation Effects
www.tektronix.com 3