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Digital Cameras . And Digital Information. How a Camera works. Light passes through the lens Shutter opens for an instant Film is exposed to light Film is developed using chemicals. Analog vs. Digital. Analog Continuous Smooth Gradations Natural capture Mechanical Digital - PowerPoint PPT Presentation
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Digital Cameras And Digital Information
How a Camera works
Light passes through the lens
Shutter opens for an instant
Film is exposed to light
Film is developed using chemicals
Analog vs. Digital
Analog Continuous Smooth Gradations Natural capture Mechanical
Digital Values measured Points and positions Binary Code Electrical
Binary Code Bit = "Binary digIT."
Binary Code: Base 2 system, 8 bit 2^0, 2^1,2^3….2^7= 8 bits
The code: 1011 (1 * 2^3) + (0 * 2^2) + (1 * 2^1) + (1 * 2^0) Conversion = 8 + 0 + 2 + 1 = 11
Bits and Bytes
8 Bits in a Byte 01100111 (Byte)
With 8 bits in a byte, you can represent 256 values ranging from 0 to 255, as shown here:
0 = 00000000 1 = 00000001 2 = 00000010 ... 254 = 11111110
255 = 11111111
Bits and Color
This is why we have a 256 color limit in an 8-bit
system
•variation of the voltage applied
•subpixel can range over 256 shades.
•Combining the subpixels produces a possible palette of 16.8 million colors (256 shades of red x 256 shades of green x 256 shades of blue
Digital Camera
Charged Coupling Device Contains array of millions
of pixels Record Light intensity Convert light in to binary
information CCD in Action
http://electronics.howstuffworks.com/digital-camera1.htm
Capturing Color CCD cells are colorblind
Only see in B/W or 1/0 RGB and CMYK filters
Allows only one color to pass through
Color Capture http://electronics.howstuffworks.com/digital-camera3.htm
CCDs and Arrays
Color Filtering Color Filter Array
Permanent Filter pattern placed on each photo site (pixel group)
Interpolation Process of using
neighboring colors to determine the true color of a pixel
Algorithm (compression) http://
electronics.howstuffworks.com/digital-camera4.htm
Resolution
Resolution Table http://fred.dsimprove.be/__offSite/pixel/static.php
The overall quality of an image Printed or Digital Standards for each DPI, PPI
printing resolution, in particular the number of individual dots of ink a printer or toner can produce within a linear one-inch space.
DPI & PPI
Dots per Inch measure of printing resolution, in
particular the number of individual dots of ink a printer or toner can produce within a linear one-inch space.
Pixels Per Inch Screen resolution of 1024x768 means
1,024 pixels (dots) horizontally across each of 768 lines (www.answers.com)
x65k or x60 hz Colors or cycles
Pixel Depth & Resolution
Bitmap Graphics Rectangular grid of pixels Color
The color of each pixel is often consist of colored pixels defined by three bytes RGB
Depth of Color image that stores 24 bits of
color information per pixel (the standard for all displays since around 1995)
1 byte for each color
How Does it Work?
Vector Graphic
based upon vector mathematical equations to represent images in computer graphics
Since the art is made from a series of mathematical formulas it will print very crisp no matter how you resize the art.
File Types & Ratings TIFF
Lossless (uncompressed) Raw Files from Cameras and Scanners 16 bit grayscale as well as 24 bit color capable commonly used file format for scientific images (no
loss of info) Very large files Not compatible with all programs
File Types & Ratings
PNG / PSD portable network graphics No Flattening (preserves layers) lossless compression supports 48-bit color and 16 grayscale, lossless
compression Supports Transparency Compatible with Original Software only
File Types & Ratings
JPEG joint photographic experts group 24-bit color lossy compression technique (discrete cosine
function) Flattened Images (no layers) Does not support Transparency!!! Compatible with all software High quality 319K, medium quality 188K
File Types & Ratings
GIF graphics exchange format Supports Transparency has a 256 color palette limitation small, limited files Compatible with all software
BMP lossless compression only 256 colors Small & simple Compatible with all software
Works Cited Structure of digital cameras http://www-users.mat.uni.torun.pl/~olka/budowa.html Binary numeral system
http://en.wikipedia.org/wiki/Binary_number#Conversion_to_and_from_other_numeral_systems
www.howstuffworks.com How Digital Cameras work www.howstuffworks.com How Cameras work