Digital Image Prep for Displays
Jim Roselli
ISF-C, ISF-R, HAA Tonight's Agenda
• A Few Basics • Aspect Ratios • LCD Display Technologies • Image Reviews Light Basics
We view the world in 3 colors Red, Green and Blue We are Trichromatic beings
We are more sensitive to Luminance than to Color Our eyes contain: • Light 4.5 million cones (color receptors) 90 million rods (lumen receptors)
Analog vs. Digital Light Sample
• Digitize the Photon Light Sample Light Sample
DSLR’s Canon 5D mkII and Nikon D3x 14 bits per color channel (16,384) Color channels (R,G & B)
• Digital Capture Digital Backs Phase One 16 bits per channel (65,536) Color channels (R,G & B) Square Pixels
Big pixels have less noise …
Spatial Resolution Round spot vs. Square pixel • Size Matters Square Pixels
• What is this a picture of ? Aspect Ratio
Using Excel’s “Greatest Common Divisor” function
• The ratio of the width to =GCD(x,y)
xRatio = (x/GCD) the height of the image yRatio = (y/GCD) on a display screen Early Television • How do I calculate this ? Aspect Ratio 4 x 3 Aspect Ratio
• SAR - Storage Aspect Ratio
• DAR – Display Aspect Ratio
• PAR – Pixel Aspect Ratio Aspect Ratio Device Width(x) Heigth(y) GCD xRa o yRa o
Display 4096 2160 16 256 135
Display 1920 1080 120 16 9
• Examples Display 1280 720 80 16 9
Display 1024 768 256 4 3
Display 640 480 160 4 3 Aspect Ratio
Device Width(x) Heigth(y) GCD xRa o yRa o
Nikon D3x 6048 4032 2016 3 2
• Examples Canon 5d mkII 4368 2912 1456 3 2 Aspect Ratio Device Width(x) Heigth(y) GCD xRa o yRa o
iPhone 1 480 320 160 3 2
HTC Inspire 800 480 160 5 3 • Examples Samsung InFuse 800 480 160 5 3 iPhone 4 960 640 320 3 2
iPad III 2048 1536 512 4 3
Motorola Xoom Tablet 1280 800 160 8 5 Future Aspect Ratio
Device Width(x) Heigth(y) GCD xRa o yRa o
Display 2048 1536 512 4 3
Display 3840 2160 240 16 9
Display 7680 4320 480 16 9 Aspect Ratio 4K Format Aspect Ratio
• Don’t be scared …
Pan D3x Frame