Lossy - Revision history

Brad Johnson at 01:38, 2 March 2019

2019-03-02T01:38:11Z

Brad Johnson at 19:31, 11 August 2017

2017-08-11T19:31:32Z

Brad Johnson at 00:26, 7 January 2012

2012-01-07T00:26:55Z

Brad Johnson at 22:54, 5 January 2012

2012-01-05T22:54:09Z

Brad Johnson at 22:44, 5 January 2012

2012-01-05T22:44:14Z

Brad Johnson at 22:36, 5 January 2012

2012-01-05T22:36:51Z

Brad Johnson: Created page with "==Overview== The term lossy is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for vi..."

2012-01-05T22:29:07Z

Created page with "==Overview== The term <nowiki>lossy</nowiki> is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for vi..."

New page

==Overview==
The term <nowiki>lossy</nowiki> is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information are based on ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes and ears.

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 ==Overview==
-The term <nowiki>lossy</nowiki> is used to describe [[data compression]] that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information employs ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes or ears.
+The term <nowiki>lossy</nowiki> is used to describe [[data compression]] that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information employs [[perceptual coding]] which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes or ears.
 ==Basics==
 The main advantage of lossy compression is that it reduces the total amount of data required to represent the original information. This typically results in smaller file size or less bandwidth required to transmit the information in exchange for absolute accuracy. One of the earliest widespread uses of lossy compression was for voice communication in telecommunications.

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 In systems like MP3 (which is actually an adaptation of the audio layer 3 of the MPEG-1 and MPEG-2 video format), the amount or degree of compression may be user selectable at the time of encoding. The higher the level of compression employed (less data), the lower the quality of the resulting audio.
 In music applications; depending on the degree of compression and the discrimination of the listener; the results may be so close to the original that the listener's impression is that it is "the same." In the case of discriminating listeners, the degree of compression often needs to be so low that there is little to be gained by using the compression or is almost the same as a file generated using lossless compression. In a noisy environment and more casual listening; moderately compressed files can often provide satisfactory results.
 One other important consideration is signal processing. The encoded signal is typically decoded to linear PCM format for processing; and applying signal processing to even decoded compressed files will generally produce inferior results compared to processing the audio prior to lossy data compression.

@@ Line 1: / Line 1: @@
 ==Overview==
-The term <nowiki>lossy</nowiki> is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information employs ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes or ears.
+The term <nowiki>lossy</nowiki> is used to describe [[data compression]] that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information employs ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes or ears.
 ==Basics==
 The main advantage of lossy compression is that it reduces the total amount of data required to represent the original information. This typically results in smaller file size or less bandwidth required to transmit the information in exchange for absolute accuracy. One of the earliest widespread uses of lossy compression was for voice communication in telecommunications.

← Older revision		Revision as of 22:54, 5 January 2012
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	There are parallels in visual technologies such as digital photography and video, with JPEG commonly used for images and MPEG for DVD video.		There are parallels in visual technologies such as digital photography and video, with JPEG commonly used for images and MPEG for DVD video.

−	In systems like MP3 (which is actually an adaptation of the audio layer 3 of the MPEG-1 and MPEG-2 video format), the amount or degree of compression may be user selectable at the time of encoding. The higher the level of compression (less data), the lower the quality of the resulting audio.	+	In systems like MP3 (which is actually an adaptation of the audio layer 3 of the MPEG-1 and MPEG-2 video format), the amount or degree of compression may be user selectable at the time of encoding. The higher the level of compression employed (less data), the lower the quality of the resulting audio.
		+
		+	In music applications; depending on the degree of compression and the discrimination of the listener; the results may be so close to the original that the listener's impression is that it is "the same." In the case of discriminating listeners, the degree of compression often needs to be so low that there is little to be gained by using the compression or is almost the same as a file generated using lossless compression. In a noisy environment and more casual listening; moderately compressed files can often provide satisfactory results.
		+
		+	One other important consideration is signal processing. The encoded signal is typically decoded to linear PCM format for processing; and applying signal processing to even decoded compressed files will generally produce inferior results compared to processing the audio prior to lossy data compression.

@@ Line 1: / Line 1: @@
 ==Overview==
-The term <nowiki>lossy</nowiki> is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information employs ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes and ears.
+The term <nowiki>lossy</nowiki> is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information employs ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes or ears.
 ==Basics==
-The main advantage of lossy compression is that it reduces the total amount of data required to represent the original information. This results in smaller file size or less bandwidth required to transmit the information in exchange for absolute accuracy. One of the earliest widespread uses of lossy compression was for voice communication in telecommunications.
+The main advantage of lossy compression is that it reduces the total amount of data required to represent the original information. This typically results in smaller file size or less bandwidth required to transmit the information in exchange for absolute accuracy. One of the earliest widespread uses of lossy compression was for voice communication in telecommunications.
 There are parallels in visual technologies such as digital photography and video, with JPEG commonly used for images and MPEG for DVD video.

← Older revision		Revision as of 22:36, 5 January 2012
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	==Overview==		==Overview==
−	The term <nowiki>lossy</nowiki> is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information ~~are based on~~ ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes and ears.	+	The term <nowiki>lossy</nowiki> is used to describe data compression that does not retain all of the original information. Most lossy compression schemes used for visual or auditory information employs ''perceptual coding'' which is based on research on how the human mind processes the <nowiki>"information"</nowiki> it receives through the eyes and ears.
		+	==Basics==
		+	The main advantage of lossy compression is that it reduces the total amount of data required to represent the original information. This results in smaller file size or less bandwidth required to transmit the information in exchange for absolute accuracy. One of the earliest widespread uses of lossy compression was for voice communication in telecommunications.
		+
		+	There are parallels in visual technologies such as digital photography and video, with JPEG commonly used for images and MPEG for DVD video.