Picture Elements PIXELS

Picture Elements
PIXELS
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PIXEL
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Un megapíxel (Mpx) equivale a 1 millón de píxeles.
Usualmente se utiliza esta unidad para expresar la resolución de
imagen de cámaras digitales.
Por ejemplo, una cámara que puede tomar fotografías con una
resolución de 2048 × 1536 píxeles se dice que tiene 3.1
megapíxeles (2048 × 1536 = 3.145.728).
0.3
1.2
2.0
3.0
5.3
6.3
11.1
640 x 480
1280 x 960
1600 x 1200
2048 x 1536
3008 x 1960
3088 x 2056
4064 x 2704
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 Each digital value is recorded as a series of binary values
known as bits.
 Each bit records an exponent of a power of 2, with the
value of the exponent determined by the position of the bit in
the sequence.
 Example: A system designed to record 7 bits for each
digital value. This means that seven binary places are
available to record the brightness sensed for each band of the
sensor.
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1 1 1 1 1 1 1 1 1 1 1
20 21 22 23 24 25 26 27 28 29 210
1 + 2 + 4 + 8 + 16 + 32 + 64 + 128 + 256 + 512 + 1024
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RADIOMETRIC DIFFERENTIATION - Examination
of any image acquired by remote sensing ultimately
depends upon detection of differences in the brightness
of objects and the features.
Radiometric Resolution: This is the sensitivity to small
differences in the radiation of an observed object.
•MSS = 6 bits
•Landsat TM = 8 bits
•ERS SAR = 16 bits
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1. Read Chapter 4 and answer
the review questions 1, 2, and 8
(at the end of the chapter).
2. Study for the exam.
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