Method and apparatus for performing various types of image processing in one operation

• US 5,425,113 A
• Filed: 12/16/1992
• Issued: 06/13/1995
• Est. Priority Date: 12/26/1991
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Ito, Wataru
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/992,821
• Time in Patent Office: 909 Days
• Field of Search: 382/6, 382/52, 382/54, 358/111, 358/447, 364/413.13, 378/98.2, 378/98.8, 378/98.6, 378/98.7
• US Class Current: 382/254
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/75 Unsharp masking

Abstract

When a visible image is reproduced from an image signal Sorg representing an image, a value of an unsharp mask signal Sus corresponding to each picture element in the image is calculated by carrying out an operation expressed as

Sus=ΣSorg/(M×N)

on values of image signal components of the image signal Sorg, which image signal components represent the picture elements falling within an area having a size corresponding to M×N number of picture elements surrounding each of the picture elements in the image. A formula is employed which is expressed as

S=γ(K1×Sorg+β(Sorg)×(K2×Sorg-D (Sus) ))

wherein γ (x) represents a function with respect to an arbitrary value x, β (Sorg) represents a function of an emphasis coefficient with respect to the image signal Sorg, D (Sus) represents an arbitrary function with respect to the unsharp mask signal Sus, and K1 and K2 represent fixed numbers. In the formula, the functions β (x), β (Sorg), and D (Sus), and the fixed numbers K1 and K2 are changed, and an operation for effecting image processing on the image signal Sorg is thereby carried out.

Claims

1. An image processing method, in which image processing is carried out on an image signal Sorg representing an image when a visible image is reproduced from the image signal Sorg,

the image processing method comprising the steps of:

i) scanning a recording material to photoelectrically detect an image physically contained thereon

ii) generating an analog output signal S₀ according to said photoelectrical detection,

iii) amplifying said analog output signal to obtain an amplified signal,

iv) converting said amplified signal into an image signal Sorg,

v) generating an unsharp mask signal Sus corresponding to each of picture elements in the image by carrying out a first operation expressed as

space="preserve" listing-type="equation">Sus=Σ

Sorg/(M×

N)

on image signal components of the image signal Sorg, which image signal components represent the picture elements falling within an area having a size corresponding to M×

N number of picture elements surrounding each of said picture elements in the image, and

vi) carrying out a second operation on said image signal Sorg in accordance with a formula

space="preserve" listing-type="equation">S=γ

(K1×

Sorg+β

(Sorg)×

(K2×

Sorg-D(Sus))

wherein said carrying out of said second operation yields an image signal S for use during reproduction of a visible image wherein γ

(x) represents a function with respect to an arbitrary value x, β

(Sorg) represents a function of an emphasis coefficient with respect to the image signal Sorg, D (Sus) represents an arbitrary function with respect to said unsharp mask signal Sus, and K1 and K2 represent fixed numbers,

said functions γ

(s), B (Sorg), and D (Sus), and said fixed numbers K1 and K2 being changed in said formula, whereby an operation for effecting image processing on the image signal Sorg is carried out

vii) feeding said image signal S into an image reproducing apparatus,

viii) reproducing a visible image signal accordance with said image signal S.

2. A method as defined in claim 1 wherein said function γ

(x) is an arbitrary function, said function β

(Sorg)=0, said fixed number K1=1, and the image processing is gradation processing.

3. A method as defined in claim 1 wherein said function γ

(x)=x, said function β

(Sorg) is an arbitrary function, said function D (Sus)=Sus, said fixed numbers K1 and K2 are set as K1=K2=1, said numbers M and N of the picture elements are set as M=N, and the image processing is frequency processing.

4. A method as defined in claim 1 wherein said function γ

(x)=x, said function β

(Sorg)=1, said function D (Sus) is an arbitrary function, said fixed number K1=1, said fixed number K2=0, said numbers M and N of the picture elements are set as M=N, and the image processing is dynamic range compression processing.

5. A method as defined in claim 1 wherein said function γ

(x)=x, said function β

(Sorg) is an arbitrary function, said function D (Sus)=Sus, said fixed numbers K1 and K2 are set as K1=K2=1, either one of said numbers M and N of the picture elements is equal to 1, and the image processing is one-dimensional unsharp mask processing.

6. A method as defined in claim 1 wherein said image is a radiation image.

7. A method as defined in claim 6 wherein said radiation image has been stored on a stimulable phosphor sheet.

8. A method as defined in claim 7 wherein an image signal, which represents said radiation image and serves as said image signal Sorg, is detected by exposing said stimulable phosphor sheet to stimulating rays, which cause said stimulable phosphor sheet to emit light in proportion to the amount of energy stored thereon during its exposure to radiation, and photoelectrically detecting the emitted light.

9. A method as defined in claim 8 wherein said stimulating rays are a laser beam.

10. A method as defined in claim 1 wherein said image is an X-ray image which has been recorded on photographic film.

11. An image processing apparatus, in which image processing is carried out on an image signal Sorg representing an image,

the image processing apparatus comprising:

i) means for scanning a recording material to photoelectrically detect an image physically contained thereon,

ii) means for generating an analog output signal S₀ in accordance with said photoelectrical detection,

iii) means for amplifying said analog output signal to obtain an amplified signal,

iv) means for converting said amplified signal into an image signal sorg,

v) a means for accepting said image signal (Sorg) into said image processing apparatus,

vi) a means for obtaining an unsharp mask signal Sus of the image signal Sorg on the basis of the image signal Sorg,

viii a means for carrying out an operation on the basis of said unsharp mask signal Sus, said operation being carried out in accordance with a formula

space="preserve" listing-type="equation">S=γ

(K1×

Sorg+β

(Sorg)×

(K2×

Sorg-D(Sus))

wherein γ

(x) represents a function with respect to an arbitrary value x, β

(Sorg) represents a function with respect to the image signal Sorg, D (Sus) represents a function with respect to said unsharp mask signal Sus, K1 and K2 represent fixed numbers, and s represents a signal for use during reproduction of a visible image and

viii) setting means for setting said functions γ

(x), β

(Sorg), and D (Sus), and said fixed numbers K1 and K2.

12. An apparatus as defined in claim 11 wherein said image is a radiation image.

13. An apparatus as defined in claim 12 wherein said radiation image has been stored on a stimulable phosphor sheet.

14. An apparatus as defined in claim 13 wherein an image signal, which represents said radiation image and serves as said image signal Sorg, is detected by exposing said stimulable phosphor sheet to stimulating rays, which cause said stimulable phosphor sheet to emit light in proportion to the amount of energy stored thereon during its exposure to radiation, and photoelectrically detecting the emitted light.

15. An apparatus as defined in claim 14 wherein said stimulating rays are a laser beam.

16. An apparatus as defined in claim 11 wherein said image is an X-ray image which has been recorded on photographic film.

17. An image processing apparatus, in which an unsharp mask signal Sus of an image signal Sorg representing an image is obtained on the basis of the image signal Sorg, and an operation for effecting image processing on the image signal Sorg is carried out on the basis of the unsharp mask signal Sus,

the image processing apparatus comprising:

i) means for scanning a recording material to photoelectrically detect an image physically contained thereon,

ii) means for generating an analog output signal S₀ in accordance with said photoelectrical detection,

iii) means for amplifying said analog output signal to obtain an amplified signal,

iv) means for converting said amplified signal into an image signal Sorg,

v) an area setting means for setting an area having a size corresponding to M×

N number of picture elements surrounding each of picture elements in the image,

vi) an unsharp mask signal generating means for generating a value of an unsharp mask signal Sus corresponding to each of said picture elements in the image by carrying out an operation expressed as

space="preserve" listing-type="equation">Sus=Σ

Sorg/(M×

N)

on values of image signal components of the image signal Sorg, which image signal components represent the picture elements falling within said area having been set by said area setting means,

vii) a D table, which stores a plurality of functions D (Sus) with respect to said unsharp mask signal Sus obtained from said unsharp mask signal operating means,

viii) a function D (Sus) setting means for setting a desired function among the plurality of said functions D (Sus) stored in said D table,

ix) an unsharp mask signal function operating means for carrying out a functional operation for said unsharp mask signal Sus on the basis of said function D (Sus), which has been set by said function D (Sus) setting means, and thereby generating an output representing the value of said function D (Sus),

x) a fixed number K1 setting means for setting a fixed number K1, by which the image signal Sorg is to be multiplied,

xi) a fixed number K1 multiplying means for multiplying the image signal Sorg by said fixed number K1, which has been set by said fixed number K1 setting means,

xii) a fixed number K2 setting means for setting a fixed number K2, by which the image signal Sorg is to be multiplied,

xiii) a fixed number K2 multiplying means for multiplying the image signal Sorg by said fixed number K2, which has been set by said fixed number K2 setting means,

xiv) a β

table, which stores a plurality of functions β

(Sorg) of an emphasis coefficient with respect to the image signal Sorg,

xv) a function β

(Sorg) setting means for setting a desired function among the plurality of said functions β

(Sorg) stored in said β

table,

xvi) an image signal function operating means for carrying out a functional operation for the image signal Sorg on the basis of said function β

(Sorg) setting means, and thereby generating an output representing the value of said function β

(Sorg),

xvii) a subtraction means for subtracting the value of said function D (Sus), which has been obtained from said unsharp mask signal function operating means, from the product of the image signal Sorg and said fixed number K2, which product has been obtained from said fixed number K2 multiplying means, and thereby generating an output representing the value of K2×

Sorg-D (SUS),

xviii) a multiplication means for multiplying the value of said function β

(Sorg), which has been obtained from said image signal function operating means, by the value of K2×

Sorg-D (Sus), which has been obtained from said subtraction means, and thereby generating an output representing the value of β

(Sorg)×

(K2×

Sorg-D (Sus)),

xix) an addition means for adding the value of β

(Sorg)×

(K2×

Sorg-D-(Sus)), which has been obtained from said multiplication means, to the product of the image signal Sorg and said fixed number K1, which product has been obtained from said fixed number K1 multiplying means, and thereby generating an output representing the value of K1×

Sorg+β

(Sorg)×

(K2×

Sorg-D (SUS)),

xx) a γ

table, which stores a plurality of functions γ

(K1×

Sorg+β

(Sorg)×

(K2×

Sorg-D (Sus) )) with respect to the value of K1×

Sorg+β

(Sorg)×

(K2×

Sorg-D (Sus)), which has been obtained from said addition means,

xxi) a function γ

setting means for setting a desired function among the plurality of said functions γ

stored in said γ

table, and

xxii) a function γ

operating means for carrying out a functional operation for the value of K1×

Sorg+β

(Sorg)×

(K2×

Sorg-D (Sus)), which has been obtained from said addition means, on the basis of said function γ

, which has been set by said function γ

setting means, and thereby generating an output signal representing the value of said function γ

(K1×

Sorg+β

(Sorg)×

(K2×

Sorg-D (Sus) ))

xxiii) means for feeding said output signal into an image reproducing apparatus,

xxiv) means for reproducing a visible image in accordance with said output signal.

18. An apparatus as defined in claim 17 wherein said image is a radiation image.

19. An apparatus as defined in claim 18 wherein said radiation image has been stored on a stimulable phosphor sheet.

20. An apparatus as defined in claim 19 wherein an image signal, which represents said radiation image and serves as said image signal Sorg, is detected by exposing said stimulable phosphor sheet to stimulating rays, which cause said stimulable phosphor sheet to emit light in proportion to the amount of energy stored thereon during its exposure to radiation, and photoelectrically detecting the emitted light.

21. An apparatus as defined in claim 20 wherein said stimulating rays are a laser beam.

22. An apparatus as defined in claim 17 wherein said image is an X-ray image which has been recorded on photographic film.