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Capture, image capture, frame grabbing – Epiphan VGA2USB Pro User Manual

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11. About Epiphan frame grabbing technology

Glossary of Terms

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Epiphan Frame Grabber

• 8 bits per pixel, grayscale 256 levels: uses a similar amount of

data as RGB 8 bpp but images are black, white, and shades of

gray. Usually you would only use 8 bpp grayscale if your

video source or codec used this color depth or to reduce file

size.

• 5 bits per pixel, grayscale 32 levels: a grayscale format that has

fewer levels of gray and uses less data than grayscale 256

levels. Usually you would only use 5 bpp grayscale if your

video source or codec used this color depth or to reduce file

size.

• Black and white: a very low quality and low data format that

uses only black and white. Usually you would only use black

and white if your video source is producing a black and white

video signal.

• 16 bits per pixel, YUY2(422), UYVY: a color format used by

many video sources. Similar to RGB 16 bpp but uses

compression and other techniques to improve the video

signal. Epiphan Frame Grabbers and the video capture

application convert YUY2(422), UYVY video images to RGB,

grayscale or black and white images.

All color depths are not supported by all video codecs or image

file formats. Most video codecs and image file formats support

RGB 24 bpp. It may be difficult to find a video codec that supports

other color depths. Some image file formats do not support all

color depths. Epiphan Frame Grabber web broadcasting operates

at RGB 24 bpp.
Epiphan Frame Grabbers capture images at the color resolution of

the video source up to the maximum resolution supported by the

Frame Grabber. The maximum resolution supported by the

VGA2USB Frame Grabber is 16 bits per pixel (bpp). The

maximum supported by all other Epiphan Frame Grabbers is 24

bpp.

Capture, image capture, frame grabbing

Epiphan products can capture VGA, DVI, or dual DVI images.

Capturing VGA data involves using a Frame Grabber to digitize

analog VGA signals and transmit the digitized images as frames

over a USB connection to the Epiphan video capture application.

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