Difference between revisions of "AY Honors/Digital Photography/Answer Key"

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===f. Describe pixels, image resolution, and image size. ===
 
===f. Describe pixels, image resolution, and image size. ===
 
===g. What are the two types of image compression? ===
 
===g. What are the two types of image compression? ===
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There are many image compression algorithms, but they can all be neatly divided into one of two types: '''lossless''' and '''lossy'''. 
 +
===Lossless Compression===
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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:
 +
 +
*[[w:Adaptive Binary Optimization|ABO]] - Adaptive Binary Optimization
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*[[W:GIF|GIF]] - (lossless, but contains a very limited number color range)
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*[[W:JBIG2|JBIG2]] - (lossless or lossy compression of B&W images)
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*[[W:JPEG-LS|JPEG-LS]] - (lossless/near-lossless compression standard)
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*[[W:JPEG 2000|JPEG 2000]] - (includes lossless compression method, as proven by Sunil Kumar, Prof San Diego State University)
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*[[W:PNG|PNG]] - Portable Network Graphics
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*[[W:TIFF|TIFF]]
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*[[W:WMPhoto|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.
 +
 +
* [[W:Fractal compression|Fractal compression]]
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* [[W:JPEG|JPEG]]
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* [[W:JPEG 2000|JPEG 2000]], JPEG's successor format that uses wavelets.
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* [[w:Wavelet compression|Wavelet compression]]
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* [[w:JBIG2|JBIG2]]
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* [[w:Cartesian Perceptual Compression|Cartesian Perceptual Compression]]: Also known as CPC
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* [[w:DjVu|DjVu]]
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* [[w:ICER|ICER]], used by the Mars Rovers: related to [[w:JPEG 2000|JPEG 2000]] in its use of wavelets
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* [[W:Hold-and-Modify|HAM]], hardware compression of color information used in [[W:Amiga|Amiga]] computers
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==2. Name and describe three types of image formats. ==
 
==2. Name and describe three types of image formats. ==
 
==3. Give the principle uses of photography: ==
 
==3. Give the principle uses of photography: ==

Revision as of 04:00, 3 May 2007

Template:Honor header

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.

e. How are lens aperture and depth of field related?

f. Describe pixels, image resolution, and image size.

g. 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.

2. Name and describe three types of image formats.

3. Give the principle uses of photography:

4. Take pictures illustrating at least eight of the following techniques. Use comparison pictures for illustration:

a. Framing.

b. Camera Steadiness.

c.Direction of lighting - front, side, or backlighting.

d. Quality of light - shade, sunlight, and time of day.

e. Rule of thirds.

f. Angle - eye level, high, and low level.

g. Level horizon.

h. Distance from subject - fill the frame.

i. Use of leading lines.

j. Correct exposure - underexposed, overexposed, and correctly exposed.

k. Use of flash - proper distance and reflective objects.

5. Learn how to place photos in PowerPoint. Create a PowerPoint presentation showing the pictures you took using the above techniques.

6. Using a photo editing program on a computer, show ability to crop, color correct, sharpen, and adjust brightness/contrast to photos.

7. Complete at least three creative photographic projects in a photo editing program; such as a CD cover, a photo scrapbook page, a collage, etc.

8. Have a basic understanding of file organization techniques.

References

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