NTSC Color Bars

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NTSC COLOR BARS

TRANSMISSION ENGINEERING

IRE ScalePicture Monitor100 90 80 70 60 50 40 30 20 10 0 -10

Waveform Monitor+100

+20

+7.5

0-20 -40

White

Black

-20 -30 -40

IRE ScalePicture Monitor100 90 80 70 60 50+46 +38 +20 +12 +7 -5 -20 -16 -16 +7.5

Waveform Monitor+100 +100 +100 +89 +77 +72

4030 20 10 0 -10 -20

FULL FIELD COLOR BARS

-30 -40

IRE ScaleWaveform Monitor Display+69 +56 +48 +44 +41 +41 +44 +31

100

+100

9080 70 60 50 40 30 20 10 0 -10 -20 -30 -40

Chrominance - only+36+28 +20 +15 +31

+7.5

Luminance - only

-20 -31 -44 -41 -41 -44 -31

IRE ScalePicture Monitor100 90 80 70 60 50 40 30 20 10 0

Waveform Monitor+100

+200 -20

+7.5

-10

Black Video

-20 -30 -40

-40

BLACK BURST SIGNAL

NTSC COMPOSITE VIDEO

Introduction For color television, the composite video signal includes the 3.58 MHz chrominance signal The color signal has a color sync burst on the back porch of horizontal sync This burst consist of 8 to 11 cycles of the 3.58 MHz color subcarrier signal Its purpose is to synchronize the 3.58 MHz color oscillator in the receiver The burst and the C signal are both 3.58 MHz, but the burst has no information

IntroductionCarrier Amplitude

Sync

Back Porch with color burstFront Porch

Back Porch with color burst

100% 75%Horizontal Retrace or blanking

67.5%

12.5%

Introduction

Horizontal Blanking IntervalBreezeway End of Active Video Leading Edge Color Burst

Trailing Edge Front Porch Horizontal Sync Pulse Back Porch Start of Active Video

Basic Video Color The color television system begins and ends with red, green and blue for color information in the scene RGB are primary colors that combined to form different mixtures Primary colors produce a wide range of color mixtures when they are added together

Basic Video ColorRED

GREEN

BLUE

Basic Video ColorYELLOW (R+G)89% 100% WHITE 59% GREEN 70% 11% BLUE 30% RED 41%

MAGENTA(R+B)

(G+B) CYAN

Basic Video Color

R G B

Basic Video ColorWHITE = R+G+B30% RED

89%

41%

100% white59% GREEN 70% 11% BLUE

Red + Cyan Green + Magenta Blue + Yellow

Basic Video Color Any color has three characteristics to specify the visual information hue or tint, which is what we generally call the color saturation, indicates how concentrated, vivid, or intense the color is Luminance, indicates the brightness, or what shade of gray the color would be in a black-and-white picture

Basic Video ColorWhite White light can be considered as a mixture of the red, green and blue in the proper proportion

Basic Video ColorHue The color itself is its hue, or tint Green leaves have a green hue Red apple has a red hue

The color of any object is distinguished primarily by its hue

Basic Video ColorSaturation Saturated color are vivid, intense, deep or strong Indicates how little the color is diluted by white vivid red is fully saturated when the red is diluted by white, the result is pink, which is really a desaturated red

Note: a fully saturated color has no white

Basic Video ColorChrominance - Chroma The term is used to combine both hue and saturation In color television, the 3.58 MHz color signal, specifically, is the chrominance signal In short, the chrominance includes all the color information, without the brightness The chrominance and brightness together specify the picture information completely

Basic Video ColorChrominance - Chroma

NORMAL

Basic Video ColorChrominance - Chroma

DESATURATED

Basic Video ColorChrominance - Chroma

SATURATED

Basic Video ColorLuminance Refers to the brightness or amount of light in the picture The dark portion of an image has a low luminance, while the light portion has a high luminance different color also have different luminance levels or shades of gray as viewed on a monochrome picture monitor

Basic Video ColorChrominance - Chroma

Basic Video ColorLuminance

Colorplexed Composite Video

30% RED1.0

R G B

0 1.0 0 1.0

89% 100% WHITE 59% GREEN 70%

41%

0

11% BLUE

1.0

Y voltage0

0.89 0.70 0.59 0.41 0.30 0.11

Relative luminance of each color

Colorplexed Composite Video

1.0 0.89

Y voltage0

0.700.59

0.41

0.30

0.11

T = Y +/- C

0.63

0.45

0.59

0.59

0.63 0.45

C signal0 0.45 1.34 1.0

0.45

0.63 1.33

0.59

0.59 1.00

0.63 0.93 0.56

1.18

0.44 0.07 0 - 0.18 0.34

EIA Standard Color Bar The early generator produced color bars that were fully saturated at 100%. This value means that R,G and B signals into the encoder are at 100% level for peak white, or 100 IRE units. This method places an unnecessary burden on the transmission equipment because of the peak excursion on the modulated 3.58 MHz chroma signal Ex. Yellow, the maximum level is 33% above peak white,owing to high luminance Also, low luminance of the blue bar result in signal amplitudes 33% below black setup

EIA Standard Color Bar

EIA Standard Color Bar The standard color-bar signal has been reduced to what is now called 75% color bar It simply means that the amplitudes of the R, G, and signals into the encoder are at 75 IRE units

EIA Standard Color Bar

EIA Standard Color Bar

EIA Standard Color Bar The values marked on the step, such as +77 for white and +28 for red, are the Y luminance levels for each of the bar For white bar, subtract 100 IRE to from 7.5 IRE setup yields 92.5 units of signal variation then taking the 75% of 92.5 units gives 69.375 units finally, putting back the 7.5 units of setup yields 76.875 approximately/rounded off to 77 IRE units For red bar, take 30% of 69.375 units for the white bar, which equals 20.813 units. then we put back the 7.5 units setup, yields 28.313 units his value is rounded off to 28 IRE unit

EIA Standard Color Bar

Y CY 77 +69 +56 +48 +36 +28 +15 B G MG R

EIA Standard Color Bar100 77 +69 +56 +48 +36 +38 +12 +28 +15 +7 100 89 G 77 72

Y CY

MG R 46 B

-5-16 -16

VITS3H 3H 3H

Vertical trace

Vertical Blanking Interval (vertical retrace/blanking)

Vertical trace

VITSLine Assignment

Vertical Synchronization - 9 lines Lines 1-3 (3H) - leading equalizing pulse Lines 4-6 (3H) - vertical sync pulse Lines 7-9 (3H) - trailing equalizing pulse

Lines 17,18 & 19 used for test signals Vertical Interval Test Signal (VITS) odd fields Line 17 - multiburst signal Line 18 - sine-squared pulse

even field Line 17 - multiburst signal Line 18 - modulated stair- steps signal

VIRSLine Assignment

Vertical Interval Reference Signal (VIRS) odd fields Line 19 - chroma and luminance reference

even fields Line 19 -chroma and luminance reference

Therefore lines 10,11,12,13,14,15 & 16 are free for other uses.