- 1、本文档共12页,可阅读全部内容。
- 2、有哪些信誉好的足球投注网站(book118)网站文档一经付费(服务费),不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
- 3、本站所有内容均由合作方或网友上传,本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺!文档内容仅供研究参考,付费前请自行鉴别。如您付费,意味着您自己接受本站规则且自行承担风险,本站不退款、不进行额外附加服务;查看《如何避免下载的几个坑》。如果您已付费下载过本站文档,您可以点击 这里二次下载。
- 4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“版权申诉”(推荐),也可以打举报电话:400-050-0827(电话支持时间:9:00-18:30)。
- 5、该文档为VIP文档,如果想要下载,成为VIP会员后,下载免费。
- 6、成为VIP后,下载本文档将扣除1次下载权益。下载后,不支持退款、换文档。如有疑问请联系我们。
- 7、成为VIP后,您将拥有八大权益,权益包括:VIP文档下载权益、阅读免打扰、文档格式转换、高级专利检索、专属身份标志、高级客服、多端互通、版权登记。
- 8、VIP文档为合作方或网友上传,每下载1次, 网站将根据用户上传文档的质量评分、类型等,对文档贡献者给予高额补贴、流量扶持。如果你也想贡献VIP文档。上传文档
查看更多
Visibility of DCT basis functions Effects of contrast masking
Solomon, J. A., Watson, A. B. Ahumada, A. (1994). Visibility of DCT basis functions: Effects of
contrast masking. Proceedings, Data Compression Conference, Snowbird, Utah: IEEE Computer
Society Press, 361-370.
Visibility of DCT basis functions:
Effects of contrast masking.
Joshua A. Solomon Andrew B. Watson Albert Ahumada
NASA Ames Research Center
Moffett Field, CA 94035-1000
jsolomon@vision.arc.nasa.gov
INTRODUCTION
DCT image compression. The discrete cosine transform (DCT) is a
standard method by which images may be compressed. Initially, the image is
divided into 8x8-pixel blocks, each of which is then transformed into its DCT,
which is an 8x8 matrix of coefficients. Each coefficient c , specifies the
ij
magnitude of a DCT frequency (or basis function), indexed by i,j . For brevity,
we adopt a vector notation for the frequencies, so U= {i,j} and c = c . Image
U ij
1
compression occurs when each coefficeint block is quantized by dividing it,
coefficient by coefficient, by a quantization matrix (QM), and rounding to the
nearest integer. For any given block of any image, there will be an 8x8 matrix of
remainders produced by this division. The distortion introduced by this method
of image compression can be expressed as an error image, which is the inverse
transform of each of these remainder matrices. The magnitude of the entries in
the QM determine the image quality and bit-rate. Small entries yield little
compression and little distortion; large entries yield much compression and
much distortion. To effectively compress an image, one must determin
您可能关注的文档
- Searching for Narrow Graviton Resonances with the ATLAS Detector at the Large Hadron Collid.pdf
- Searching for Neutrinos from WIMP Annihilations in the Galactic Stellar Disk.pdf
- Searching for nonGaussianity in the WMAP data.pdf
- Searching for Planets in the Hyades II Some Implications of Stellar Magnetic Activity.pdf
- Searching for Supersymmetric Dark Matter The Modulation Effect Due to Caustc Rings.pdf
- Searching for SUSY Dark Matter The Directional Rate and the Modulation Effect.pdf
- Searching for threenucleon resonances.pdf
- Searching for Top Squark at Hadron Colliders.pdf
- Searching New Physics in Muonium Atom.pdf
- Searching Scalar Resonances with Ultrahigh Energy Neutrinos.pdf
文档评论(0)