Introduction to the Digital Darkroom

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Introduction to the Digital Darkroom
INTRODUCTION TO THE DIGITAL DARKROOM

• JOHN KEZYS
• The Hubble Deep Field 2002 September 1
• Credit R. Williams, The HDF Team (STScI), NASA
• Explanation Galaxies like colorful pieces of
  candy fill the Hubble Deep Field - one of
  humanity's most distant optical views of the
  Universe. The dimmest, some as faint as 30th
  magnitude (about four billion times fainter than
  stars visible to the unaided eye), are very
  distant galaxies and represent what the Universe
  looked like in the extreme past, perhaps less
  than one billion years after the Big Bang. To
  make the Deep Field image, astronomers selected
  an uncluttered area of the sky in the
  constellation Ursa Major (the Big Bear) and
  pointed the Hubble Space Telescope at a single
  spot for 10 days accumulating and combining many
  separate exposures. With each additional
  exposure, fainter objects were revealed. The
  final result has been used to explore the
  mysteries of galaxy evolution and the infant
  Universe.

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Mariner 4 TV Image
The spacecraft had a television camera, which
took 22 television pictures covering about 1 of
the planet. These pictures took four days to
transmit to Earth.
Heavily cratered area in Memnonia Fossae on Mars
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The First CCD Camera
Willard Boyle and George Smith developed the
first CCD camera at Bell Labs in 1974.
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Photography Vs. CCD Imaging

• film records only 0.5 of the light

• CCDs are 90 quantum efficient

- astronomers would require 45 minutes of
exposure
time with film while the same results can
be had with 15 second exposure using a CCD
camera
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Photography Vs. CCD Imaging

• film records only 0.5 of the light
• film is prone to reciprocity failure

• CCDs are 90 quantum efficient
• CCDs are highly linear

- lengthy exposure times cause photographic film
to lose contrast and there are colour shifts
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Photography Vs. CCD Imaging

• film records only 0.5 of the light
• film is prone to reciprocity failure
• most films are sensitive to only visible
  wavelengths

• CCDs are 90 quantum efficient
• CCDs are highly linear
• CCDs are sensitive to a much wider wavelength
  range

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Pictures are Numbers

• pixel values of the top
• left corner

each pixel is defined by an 8 bit binary number
and it can take on one of 28 or 256 grey scale
values
0 value is black 255 value is white
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GRAPHIC IMAGE FILE
Bit Depth Determines Image Detail - the larger
the bit depth or word size the more graduated the
grey scale and the finer the image detail
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Bit Depth
1 bit
2 bit
4 bit
3 bit
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Colour Imaging
A 24 bit colour depth refers to 8 bit allocation
to Red, Green and Blue channels
Bayer Pattern for Colour CCD Array
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CCD Camera Technology
CX161 Ultra-compact CCD Colour Board Camera Less
Than 1" Square
Sinar p3 View Camera
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LAB 4 Image Processing
http//spinroot.com/pico/
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Only From Photoshop
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GRAPHIC IMAGE FILE

• - the computer industry supports an insane number
  of graphic file formats ....
• TIFF, PCX, GIF, GEM, TARGA, BMP, JPEG,
• FITS, PIC, CDX, WPG, CDR, PCL, DXF,
• EPS, RIFF, SGI, CGM ........

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The KAF-16801 is designed to meet the demanding
requirements of the studio and high-end digital
camera marketplace. Its 16.6 million (4080 x
4080) pixel array represents an unprecedented
leap in CCD resolution. The device incorporates a
9 micron pixel architecture with integral color
filter array and is packaged in a 34-pin DIP
ceramic package. Studio photographers in the
professional market demand uncompromising image
quality. The KAF-16801CE, with its ultra-high
resolution and large pixel size, meets their
requirements by providing superior dynamic range
and low noise. The result is stunning digital
images with exceptional sharpness. 3500 US in
quantities of 1000
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The Mariner mission produced fuzzy images which
were yhe basis of the first intensive application
of image processing algorithms. The image was
taken from 12,600 km and covers 250 km by 254 km.
North is up. first pictures of the martian
surface. flew by Mars on July 14 and 15, 1965.
Imaging with a vidicon camera of 22 images where
each image took 4 days to transmit. First
evidence of craters
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QUANTUM EFFICIENCY OF VARIOUS SENSORS
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Charged Coupled Device Chip
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newr,a einsteinsqrt(r x R),a
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How many pixels does it take for a CCD to
outperform 35mm film?

• December 2002 - the Canon EOS-1Ds raises
  resolution to 11 megapixels.
• 9,000 at Henrys
• the eye is 120 megapixel camera

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How many pixels does it take for a CCD to
outperform 35mm film?

• World's first digital SLR that can prove its
  images are unaltered, original files.
• The CCD chip captures a full 35 mm frame.