Difference between revisions of "AY Honors/Digital Photography/Answer Key"
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< AY Honors | Digital PhotographyAY Honors/Digital Photography/Answer Key
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===c. How color images are created from the BW image the sensor captures. === | ===c. How color images are created from the BW image the sensor captures. === | ||
===d. What the camera lens does; what focal length means. === | ===d. What the camera lens does; what focal length means. === | ||
− | == | + | ==2. How are lens aperture and depth of field related? == |
− | == | + | ==3. Describe pixels, image resolution, and image size. == |
− | == | + | ==4. What are the two types of image compression? == |
There are many image compression algorithms, but they can all be neatly divided into one of two types: '''lossless''' and '''lossy'''. | There are many image compression algorithms, but they can all be neatly divided into one of two types: '''lossless''' and '''lossy'''. | ||
===Lossless Compression=== | ===Lossless Compression=== |
Revision as of 04:20, 3 May 2007
1. Explain the following:
a. The principles of digital camera construction and how a digital camera works.
b. The effect of light on an image sensor.
c. How color images are created from the BW image the sensor captures.
d. What the camera lens does; what focal length means.
3. Describe pixels, image resolution, and image size.
4. What are the two types of image compression?
There are many image compression algorithms, but they can all be neatly divided into one of two types: lossless and lossy.
Lossless Compression
In lossless compression, when the image is restored from the compressed format, it is an exact binary match to the original. Every bit is exactly the same as in the original. Examples of lossless image compression file formats include:
- ABO - Adaptive Binary Optimization
- GIF - (lossless, but contains a very limited number color range)
- JBIG2 - (lossless or lossy compression of B&W images)
- JPEG-LS - (lossless/near-lossless compression standard)
- JPEG 2000 - (includes lossless compression method, as proven by Sunil Kumar, Prof San Diego State University)
- PNG - Portable Network Graphics
- TIFF
- WMPhoto - (includes lossless compression method)
Lossy Compression
With lossy compression, the uncompressed image is not exactly the same, but it can be very difficult to tell the difference with the naked eye. By permanently throwing away some of the information in the image, the file can be made much smaller.
- Fractal compression
- JPEG
- JPEG 2000, JPEG's successor format that uses wavelets.
- Wavelet compression
- JBIG2
- Cartesian Perceptual Compression: Also known as CPC
- DjVu
- ICER, used by the Mars Rovers: related to JPEG 2000 in its use of wavelets
- HAM, hardware compression of color information used in Amiga computers