The digital camera, like the standard film camera, uses a lens to focus the image on a sensor.

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Digital Photography

Digital photography, which is also called 'digital imaging' since it does not involve the use of film started in the sixties. The original development of the technology is at NASA when they required that exploration spacecraft, unable to return to earth, to be capable of sending back pictures of their voyages.

The digital camera, like the standard film camera, uses a lens to focus the image on a sensor. The usual film camera depends on a film to capture the image but the digital relies on a sensor, either CCD or CMOS . As light hits the pixels that make up the sensor, it is converted to a current that is then sent to the 'Analogue to Digital Converter' or A-D converter.

When a photo is digitised, its colours are sampled from the sensor and converted to binary format. The smallest image element sampled is called a pixel. The digital image is like a map, where the information about the colour value of a pixel is understood as co-ordinates on the map. When the map is converted back to an image, the pixel goes to its position and colour in relation to the other pixels making up the image and the co-ordinates given to it.

From the A-D converter, algorithms are then applied to the data converting it into a digital image. Sometimes, the size of the data generated by an image sensor can be very large. The larger the number of pixels making up the picture, the higher the resolution of the image and the larger the size of the data of the image. To deal with these large files, most digital cameras compress the data, as to make the size of the data of the image smaller. The way the data representing an image is electronically written is called an 'image file format'.
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There are many different image file formats. Several of them use compression techniques to reduce the storage space required by the bitmap image data. These compression methods are classified in two ways: whether or not they remove detail and colour from the image. 'Lossless' methods compress image data without removing any detail from the image, while 'lossy' methods compress images by removing detail and colour depth. One of the more common standards of compression for digital cameras is the JPEG format.

The larger the image, and the more precise the sampling process, the larger the final ...

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