US 7,548,656 B2Granted

Method and apparatus for processing image signals by applying a multi-resolution conversion processing for reducing the image size and applying a dyadic wavelet transform

AssigneeKonica Minolta Holdings, Inc.

InventorsTakeshi Nakajima, Tsukasa Ito, Tsuyoshi Hattori, Shoichi Nomura, Chizuko Ikeda

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Abstract

There are described image-processing method and apparatus, which make it possible to reduce the processing load even in the image-processing environment employing the Dyadic Wavelet transform. The apparatus includes a reading section to read an image recorded on a recording medium so as to generate image signals representing the image; a first converting section to apply a multi-resolution conversion processing of at least level 1, which is capable of reducing an image size of the image signals, to the image signals, so as to generate first-converted image signals from the image signals; and a second converting section to apply a Dyadic Wavelet transform of at least level 1 to low frequency band component signals included in the first-converted image signals, so as to generate second-converted image signals from the first-converted image signals. An image size of the first-converted image signals is smaller than that of the image signals.

Claims32

Dependent claims

A method for processing image signals, comprising:

reading an image recorded on a recording medium so as to generate image signals representing said image;
applying, to said image signals, using a processing unit, a multi-resolution conversion processing of at least level 1, which is capable of reducing an image size of said image signals, so as to generate first-converted image signals from said image signals;
and
applying a Dyadic Wavelet transform of at least level 1 to lowest frequency band component signals included in said first-converted image signals, so as to generate second-converted image signals from said first-converted image signals;
wherein no down-sampling is performed in said Dyadic Wavelet transform, and wavelet function ψi,j (x) to be employed in said Dyadic Wavelet transform is defined by an equation shown below:

ψ
⁢
i
,
j
⁢
(
x
)
=
2
-
i
⁢
ψ
⁡
(
x
-
j
2
i
)

where “i” and “j” denote natural numbers;
wherein an image size of said first-converted image signals is smaller than the image size of said image signals, while an image size of said second-converted image signals is identical to the image size of said first-converted image signals;
wherein the method further comprises determining a changeover level from said multi-resolution conversion processing to said Dyadic Wavelet transform, based on a resolution of said read image signals;
and
wherein said multi-resolution conversion processing is applied to said image signals according to said determined changeover level, and said Dyadic Wavelet transform is applied to said low frequency band component signals according to said determined changeover level.

32 more elements

An apparatus for processing image signals, comprising:

a processing unit;
a reading section to read an image recorded on a recording medium so as to generate image signals representing said image;
a first converting section to apply a multi-resolution conversion processing of at least level 1, which is capable of reducing an image size of said image signals, to said image signals read by said reading section, so as to generate first-converted image signals from said image signals;
and
a second converting section to apply a Dyadic Wavelet transform of at least level 1 to low frequency band component signals included in said first-converted image signals generated by said first converting section, so as to generate second-converted image signals from said first-converted image signals;
wherein no down-sampling is performed in said Dyadic Wavelet transform, and wavelet function ψi,j (x) to be employed in said Dyadic Wavelet transform is defined by an equation shown below:

ψ
⁢
i
,
j
⁢
(
x
)
=
2
-
i
⁢
ψ
⁡
(
x
-
j
2
i
)

where “i” and “j” denote natural numbers;
wherein an image size of said first-converted image signals is smaller than the image size of said image signals, while an image size of said second-converted image signals is identical to the image size of said first-converted image signals;
wherein the apparatus further comprises a determining section to determine a changeover level from said multi-resolution conversion processing to said Dyadic Wavelet transform, based on a resolution of said image signals read by said reading section;
and
wherein said first converting section applies said multi-resolution conversion processing to said image signals according to said changeover level determined by said determining section, and said second converting section applies said Dyadic Wavelet transform to said low frequency band component signals according to said changeover level determined by said determining section.

33 more elements

A computer readable storage medium storing a computer program that is executable by a computer to cause the computer to conduct operations for processing image signals, the program being executable by the computer to cause the computer to perform a process comprising:

reading an image recorded on a recording medium so as to generate image signals representing said image;
applying, to said read image signals, a multi-resolution conversion processing of at least level 1, which is capable of reducing an image size of said image signals, so as to generate first-converted image signals from said image signals;
and
applying a Dyadic Wavelet transform of at least level 1 to low frequency band component signals included in said first-converted image signals, so as to generate second-converted image signals from said first-converted image signals;
wherein no down-sampling is performed in said Dyadic Wavelet transform, and wavelet function ψi,j (x) to be employed in said Dyadic Wavelet transform is defined by an equation shown below:

ψ
⁢
i
,
j
⁢
(
x
)
=
2
-
i
⁢
ψ
⁡
(
x
-
j
2
i
)

where “i” and “j” denote natural numbers;
wherein an image size of said first-converted image signals is smaller than the image size of said image signals, while an image size of said second-converted image signals is identical to the image size of said first-converted image signals;
wherein said processing section further comprises a determining section to determine a changeover level from said multi-resolution conversion processing to said Dyadic Wavelet transform, based on a resolution of said image signals read by said reading section;
and
wherein said first converting section applies said multi-resolution conversion processing to said image signals according to said changeover level determined by said determining section, and said second converting section applies said Dyadic Wavelet transform to said low frequency band component signals according to said changeover level determined by said determining section.

32 more elements

An apparatus for recording an output image onto an outputting medium, comprising:

a processing unit;
a reading section to read an image formed on a recording medium so as to generate image signals representing said image;
a processing section to process said image signals so as to generate output image signals representing said output image;
and
a recording section to record said output image onto said outputting medium, based on said output image signals generated by said processing section;
wherein said processing section comprises:
a first converting section to apply a multi-resolution conversion processing of at least level 1, which is capable of reducing an image size of said image signals, to said image signals read by said reading section, so as to generate first-converted image signals from said image signals;
and
a second converting section to apply a Dyadic Wavelet transform of at least level 1 to low frequency band component signals included in said first-converted image signals generated by said first converting section, so as to generate second-converted image signals from said first-converted image signals;
wherein no down-sampling is performed in said Dyadic Wavelet transform, and wavelet function ψi,j (x) to be employed in said Dyadic Wavelet transform is defined by an equation shown below:

ψ
⁢
i
,
j
⁢
(
x
)
=
2
-
i
⁢
ψ
⁡
(
x
-
j
2
i
)

where “i” and “j” denote natural numbers;
wherein an image size of said first-converted image signals is smaller than the image size of said image signals, while an image size of said second-converted image signals is identical to the image size of said first-converted image signals;
wherein said processing section further comprises a determining section to determine a changeover level from said multi-resolution conversion processing to said Dyadic Wavelet transform, based on a resolution of said image signals read by said reading section;
and
wherein said first converting section applies said multi-resolution conversion processing to said image signals according to said changeover level determined by said determining section, and said second converting section applies said Dyadic Wavelet transform to said low frequency band component signals according to said changeover level determined by said determining section.

37 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/754,003Filed 8 Jan 2004
Priority: JP 2003-00821716 Jan 2003
Published: US 2004/0234166 A125 Nov 2004
Granted: 16 Jun 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G06T 5/10
Image enhancement or restoration: using non-spatial domain filtering
G06T 5/70
Image enhancement or restoration: denoising; Smoothing
G06T 9/007
Image coding: transform coding, e.g. discrete cosine transform
G06T 2207/20016
Special algorithmic details: hierarchical, coarse-to-fine, multiscale or multiresolution image processing; Pyramid transform