Picture Elements PIXELS
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Picture Elements PIXELS 1 PIXEL 2 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 3 4 5 6 7 8 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. 9 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 10 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 11 12 13 1. Read Chapter 4 and answer the review questions 1, 2, and 8 (at the end of the chapter). 2. Study for the exam. 14
