Title:
順方向および逆離散コサイン変換の効率的な固定小数点近似
Document Type and Number:
Japanese Patent JP2010505287
Kind Code:
A
Abstract:
Techniques are described to approximate computation of an inverse discrete cosine transform using fixed-point calculations. According to these techniques, matrixes of scaled coefficients are generated by multiplying coefficients in matrixes of encoded coefficients by scale factors. Next, matrixes of biased coefficients are generated by adding a midpoint bias value to a DC coefficient of the matrix of scaled coefficients. Fixed-point arithmetic is then used to apply a transform to the matrixes of biased coefficients. Values in the resulting matrixes are then right-shifted in order to derive matrixes of pixel component values. Matrixes of pixel component values are then combined to create matrixes of pixels. The matrixes of pixels generated by these techniques closely resemble matrixes of pixels decompressed using the ideal inverse discrete cosine transform ('IDCT').
Inventors:
Lesnik, Yury
Application Number:
JP2009518523A
Publication Date:
February 18, 2010
Filing Date:
June 26, 2007
Export Citation:
Assignee:
QUALCOMM INCORPORATED
International Classes:
H04N7/30; G06F17/14; H04N1/41
Other References:
JPN6012009030; Ｃｉ-ｘｕｎ Ｚｈａｎｇ， Ｊｉｎｇ Ｗａｎｇ， Ｌｕ Ｙｕ，: 'Ｓｙｓｔｅｍａｔｉｃ Ａｐｐｒｏａｃｈ ｏｆ Ｆｉｘｅｄ Ｐｏｉｎｔ ８ｘ８ ＩＤＣＴ ａｎｄ ＤＣＴ Ｄｅｓｉｇｎ ａｎｄ Ｉｍｐｌｅｍｅｎｔａｔｉｏｎ' ＰＣＳ ２００６ , 200604
JPN6012009030; Ｃｉ-ｘｕｎ Ｚｈａｎｇ， Ｊｉｎｇ Ｗａｎｇ， Ｌｕ Ｙｕ，: 'Ｓｙｓｔｅｍａｔｉｃ Ａｐｐｒｏａｃｈ ｏｆ Ｆｉｘｅｄ Ｐｏｉｎｔ ８ｘ８ ＩＤＣＴ ａｎｄ ＤＣＴ Ｄｅｓｉｇｎ ａｎｄ Ｉｍｐｌｅｍｅｎｔａｔｉｏｎ' ＰＣＳ ２００６ , 200604
JPN6012009030; Ｃｉ-ｘｕｎ Ｚｈａｎｇ， Ｊｉｎｇ Ｗａｎｇ， Ｌｕ Ｙｕ，: 'Ｓｙｓｔｅｍａｔｉｃ Ａｐｐｒｏａｃｈ ｏｆ Ｆｉｘｅｄ Ｐｏｉｎｔ ８ｘ８ ＩＤＣＴ ａｎｄ ＤＣＴ Ｄｅｓｉｇｎ ａｎｄ Ｉｍｐｌｅｍｅｎｔａｔｉｏｎ' ＰＣＳ ２００６ , 200604
Attorney, Agent or Firm:
Takehiko Suzue
Kurata Masatoshi
Satoshi Kono
Makoto Nakamura
Yoshihiro Fukuhara
Takashi Mine
Toshio Shirane
Sadao Muramatsu
Nobuhisa Nogawa
Kocho Chojiro
Naoki Kono
Katsu Sunagawa
Tetsuya Kazama
Katsumura Hiro
Shoji Kawai
Tatsushi Sato
Takashi Okada
Mihoko Horiuchi
Takenori Masanori
Takuzo Ichihara
Yamashita Gen
Kurata Masatoshi
Satoshi Kono
Makoto Nakamura
Yoshihiro Fukuhara
Takashi Mine
Toshio Shirane
Sadao Muramatsu
Nobuhisa Nogawa
Kocho Chojiro
Naoki Kono
Katsu Sunagawa
Tetsuya Kazama
Katsumura Hiro
Shoji Kawai
Tatsushi Sato
Takashi Okada
Mihoko Horiuchi
Takenori Masanori
Takuzo Ichihara
Yamashita Gen