WO2005117412A1 - 画像処理方法、画像処理プログラムおよび画像処理装置 - Google Patents
画像処理方法、画像処理プログラムおよび画像処理装置 Download PDFInfo
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- WO2005117412A1 WO2005117412A1 PCT/JP2005/008972 JP2005008972W WO2005117412A1 WO 2005117412 A1 WO2005117412 A1 WO 2005117412A1 JP 2005008972 W JP2005008972 W JP 2005008972W WO 2005117412 A1 WO2005117412 A1 WO 2005117412A1
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- color gamut
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/46—Colour picture communication systems
- H04N1/56—Processing of colour picture signals
- H04N1/60—Colour correction or control
Definitions
- Image processing method image processing program, and image processing apparatus
- the present invention relates to an image processing method, an image processing program, and an image processing device.
- a photographic photosensitive material such as a color or black-and-white negative film or a reversal film on which an image is recorded by an analog camera, or a storage medium (hereinafter, referred to as a medium) on which an image is captured by a digital camera.
- a storage medium hereinafter, referred to as a medium
- color or black-and-white photographic paper such as silver halide photographic paper on which images have been recorded.
- Image information is read to create image data, and color balance and brightness are applied to the original image corresponding to the image data.
- an image processing apparatus which performs image processing for changing the image data and outputs image data for output (for example, see Patent Document 1).
- the following method is generally employed. That is, first, at the time of the rough reading, the light of each color of R (red), G (green), and B (blue) is transmitted or reflected by a film or a photographic paper, and the R GB is read by a CCD or the like. The color density is separately measured, and image data is created for each pixel of the original image. Then, at the time of image processing, the color density of each of the RGB colors of the image data is changed based on, for example, a one-dimensional LUT (Look Up Table) as shown in FIG.
- a one-dimensional LUT Look Up Table
- a process (correction) of emphasizing blue for an original image on a display device such as a monitor of an image processing device is performed.
- a display device such as a monitor of an image processing device
- image processing to increase the brightness of the entire image can be performed by making changes to increase the color densities of all R, G, and B of the image data of each pixel based on the LUT for each of RGB. ).
- Such an image processing method can easily and quickly change the color density of each of the RGB colors in the force image data performed on each pixel of the original image by LUT conversion. Perspective of easiness This is a very effective method.
- the dark green pixel portion has a B component as shown in FIG. While the color density is changed so that the change in the G component is greater than the change, in the bright green pixel portion, the change in the B component is A phenomenon occurs in which the color density is changed so as to be larger than the change.
- the color density is changed using a large change amount LUT as shown in FIG. 27 for each of the RGB colors.
- the output value obtained by the change exceeds the output possible range of the display means (for example, 0 to 255), it cannot be output. Therefore, if the output value exceeds the maximum value (255 in this case), For that input value, it is necessary to perform clipping processing to suppress the output value of the corresponding color density to the maximum value that can be taken (see the dotted line in the figure).
- the output value is clipped for a group of pixels that already have a high color density of R.
- the pixel portion hardly increases redness, and it does not respond to changes in hue of surrounding pixels. The color becomes unnatural only in the pixel portion of.
- the result of the image processing is not always the expected processing result, and it is not always easy to perform a precise color tone adjustment.
- Patent document 1 JP-A-9-163163
- An object of the present invention is to provide an image processing method, an image processing program, and an image processing apparatus capable of performing assumed color reproduction without changing hue in image processing of an image or the like read from a film. To provide.
- a function represented by an output value f (input value)
- a unit change amount with respect to a predetermined input value is defined, and based on the function and the unit change amount, an LUT created for each of the brightness component and the color component is used, or based on the function and the unit change amount.
- the color density change processing is performed to change each of the lightness component and the color component of the color density of each pixel by calculation.
- a determination process for determining whether or not the pixel after the color density change process is within the defined color gamut, and a determination that the pixel after the color density change process is outside the definition color gamut by the determination process it is preferable to perform a color gamut compression process of displacing the pixel after the color density changing process into a defined color gamut while maintaining its hue constant.
- An LUT is created for each of the lightness component and the color component based on the unit change amount defined for a predetermined input value of the function and the function, and the lightness component and the color component of the color density of each pixel are created.
- the computer may determine whether or not the pixel after the color density change processing is within a defined color gamut. If the computer determines that the pixel after the color density change processing is outside the defined color gamut, Preferably, the pixel after the color density change processing functions as a means for performing a color gamut compression processing for displacing the pixel within a defined color gamut while maintaining its hue constant.
- the image processing apparatus of the present invention includes a control unit that acquires image data of each pixel and performs image processing, and an operation unit that issues an instruction to the control unit.
- a unit change amount defined for a predetermined input value of a function represented by output value f (input value)
- a LUT is created for each of the lightness component and the color component based on the function, or a color density that is changed for each of the lightness component and the color component of the color density of each pixel by calculation based on the function and the unit change amount It has a change processing means.
- control unit determines whether or not the pixel after the color density change processing is within the defined color gamut, and determines that the pixel after the color density change processing is outside the defined color gamut.
- a color gamut compression processing means for performing color gamut compression processing for displacing the pixel after the color density change processing within the defined color gamut while maintaining its hue constant.
- FIG. 2 is a schematic diagram showing an operation unit of the image processing apparatus according to the embodiment.
- FIG. 3 is a block diagram showing a schematic configuration centering on a control unit of the image processing apparatus of the present embodiment.
- FIG. 4 is a view showing a point S corresponding to a color density of a target pixel in an L * a * b * color space.
- FIG. 5 is a diagram showing LUTs in the case of “+ M” processing.
- FIG. 5A shows LUTs for L * components
- FIG. 5B shows LUTs for a * components
- FIG. 6 is a diagram showing a state in which the color density of the pixel of interest is changed in the L * a * b * color space based on the LUT in FIG.
- FIG. 7 is a diagram illustrating the relationship between a vector Y, a vector ⁇ , and a vector C.
- FIG. 8 is a table showing regulation values used in regulation processing.
- FIG. 9 ( ⁇ ) is a diagram explaining the brightness, saturation and hue of the pixel in the L * a * b * color space, and (B) is a diagram illustrating the saturation of the pixel in the a * b * plane. And FIG. [10] FIG. 10 is a diagram illustrating a defined color gamut on an LC plane.
- FIG. 11 is a diagram illustrating a defined color gamut of another shape on the LC plane.
- FIG. 13 is a diagram illustrating a process of determining whether or not a target pixel is within a defined color gamut.
- FIG. 14 is a diagram for describing a method of dividing an out-of-definition color gamut region into three parts.
- FIG. 15 is a diagram for describing processing in a case where saturation becomes 0 before a target pixel reaches a defined color gamut boundary in color gamut compression.
- FIG. 16 is a diagram for explaining processing in the case where the brightness changes significantly before and after compression in color gamut compression.
- FIG. 17 is a flowchart showing a procedure of an image processing method using an image processing program.
- FIG. 18 is a diagram for explaining that a vector M of the “+ M” process faces in the same direction on the a * b * plane.
- FIG. 19 is a diagram for explaining that the inclination of the vector M changes depending on the position in the L * -axis direction in the “+ M” process.
- FIG. 20 is a diagram illustrating displacement of a point by a color gamut compression method different from that of the present embodiment.
- FIG. 21 is a diagram illustrating displacement of a point by the color gamut compression method of the present embodiment.
- FIG. 22 is a diagram showing a first modification of the operation unit.
- FIG. 23 illustrates a second modification of the operation unit.
- FIG. 24 is a diagram showing an LUT used in conventional image processing.
- FIG. 25 is a diagram showing a change in green color density when a conventional LUT is used.
- FIG. 26 is a diagram showing a change in the color density of bright green when a conventional LUT is used.
- FIG. 27 is a diagram showing an LUT with clipping processing used in conventional image processing.
- FIG. 28 is a diagram showing LUT with clipping processing used when weakening color density in conventional image processing.
- FIG. 1 is a perspective view showing an embodiment of an image processing apparatus according to the present invention.
- a transparent original input device 3 and a reflective original input device 4 are arranged on the upper part of the main body 2 of the image processing apparatus 1.
- the transparent original input device 3 reads image information from a film such as a color negative film, a color reversal film, a black and white negative film, a black and white reversal film with a film scanner, and the reflective original input device 4 uses a flatbed scanner with color or black and white. It is configured to read image information and convert it into digital information to create image data.
- An image reading unit 5 is provided on the front of the main body of the image processing apparatus 1.
- a floppy (registered trademark) disk (hereinafter referred to as FD) 6 in which a plurality of pieces of frame image information are captured by a digital camera and can be inserted into the image reading unit 5 is provided.
- a PC card adapter 9 to which a PC card 8 having a memory storing a frame 7 and similar frame image information can be inserted is provided.
- the reading unit (not shown) of each of the adapters 7 and 9 is configured to read the image information of each media, convert the image information into digital information, and create image data! Puru.
- the image processing apparatus 1 further includes a compact flash (registered trademark) in which image information is stored by an imaging device such as a digital camera, a memory stick, a smart media, a multimedia card, Portable media such as magneto-optical storage media (MO), CD-R, DVD etc.
- a compact flash registered trademark
- image information is stored by an imaging device such as a digital camera, a memory stick, a smart media, a multimedia card, Portable media such as magneto-optical storage media (MO), CD-R, DVD etc.
- Means for reading image information and means for acquiring digital image information via communication means such as a network are provided. .
- an image corresponding to the image data is displayed on the screen on the upper part of the main body of the image processing apparatus 1.
- a CRT 10 as a display means for displaying images is provided, and an operation unit 11 including a keyboard and a panel having dedicated buttons for performing image processing while viewing the screen of the CRT 10 is provided in front of the CRT 10. You. It is also possible to adopt a configuration such as a touch panel monitor in which the functions of the CRT 10 and the operation unit 11 are integrated.
- the operation unit 11 is provided with various function buttons for issuing an image processing instruction to each device constituting the image processing apparatus 1 via the control unit of the image processing apparatus 1. Have been killed. Further, the operation unit 11 is provided with at least a color correction processing button such as “+ Y” as shown in FIG.
- Y, M, and C represent the colors of yellow, magenta, and cyan, respectively. “+” Increases the color density of the color, and “one” decreases (decreases) the color density of the color. ) Means that the correction process is performed.
- the “+ Y” button makes the entire image displayed on the screen of the CRT 10 yellowish
- the “ ⁇ ” button shows the color density so that the entire image becomes bluish. It is an operation button for changing.
- the color correction processing by the operation of the operation unit 11 may be configured to be performed using, for example, RGB.
- the operation unit 11 is also provided with various buttons for performing other image processing.
- D represents density correction processing of the entire image
- T represents Indicates contrast adjustment processing.
- the “+ D” button decreases the brightness of the entire image (ie, darkens), and the “+ T” button increases the contrast of the entire image (ie, makes it harder).
- image processing in addition to the above-described color correction processing, density correction processing, contrast adjustment processing, color enhancement processing, sharpness processing, noise suppression processing, soft focus processing, backlight correction processing, partial gradation adjustment processing, etc.
- the image processing method of the present invention can also be applied to those cases.
- the image processing apparatus 1 of the present embodiment also has a print output function of exposing and developing image data subjected to image processing on a photosensitive material to produce a print.
- a magazine loading section 12 loaded with photosensitive material is attached to one side of the main body 2 of the image processing apparatus 1, and the magazine loading section 12 loads photosensitive materials of various sizes into the main body 2. like It is configured.
- the main body 2 is provided with an exposure processing section 13 for exposing the photosensitive material, and a print producing section 14 for developing and drying the exposed photosensitive material to produce a print.
- the created print is discharged to a tray 15 provided on the other side of the main body 2.
- an image writing unit 16 for storing image-processed image data on a medium is provided on the front of the main body of the image processing apparatus 1, and the FD 6 is inserted into the image writing unit 16.
- An FD adapter 17 that can be inserted, an MO adapter 19 that can insert an MO 18, and an optical disk adapter 21 that can be inserted an optical disk 20 are provided. It can be stored.
- a means for writing image data to other portable media a means for transmitting digital image data subjected to image processing via communication means such as a network, and the like.
- control unit for controlling the above devices and the like.
- the control unit uses a computer configured by connecting a CPU, a RAM, a ROM, an input / output interface, and the like via a BUS.
- the control unit 22 is connected to data storage means 23 including a storage medium such as a hard disk.
- data storage means 23 including a storage medium such as a hard disk.
- the control unit 22 digitizes the image information.
- the stored image data is transmitted to the data storage means 23 and is sequentially stored.
- the control unit 22 performs the following image processing based on an instruction from the operation unit 11.
- the processed image data is read from the data storage unit 23 and transmitted to the image writing unit 16, and the image writing unit 16 writes the image data on a medium such as the FD 6, the MO 18, and the optical disk 20.
- the control unit 22 transmits the processed image data to the exposure processing unit 13 and the print production unit 14 based on an instruction from the operation unit 11, and outputs the service size, the high-definition size, the panorama size, the A4 size, and the business card. It is configured to produce prints of various sizes such as sizes.
- control unit 22 develops an image processing program stored in the ROM of the control unit 22 on the RAM based on an instruction from the operation unit 11, and performs image processing based on the image processing program. It is configured to perform.
- the image processing program is configured to cause the control unit 22 of the image processing apparatus 1 as a computer to execute a color density change process, a determination process, and a gamut compression process as necessary. Being done.
- the control unit 22 can also be applied to a case where the image data is processed on the RAM without displaying the image on the CRT 10 to automatically correct the color correction and the density correction of the image.
- each process such as a color density change process is performed in a CIE 1976 L * a * b * color space (hereinafter referred to as an L * a * b * color space) as a uniform color space. If it is a space, it is not particularly necessary to limit to the L * a * b * color space.
- each process can be similarly performed in the Munsell color space or the CIE1976L * u * v * color space.
- the control unit 22 selects a pixel (hereinafter, referred to as a pixel of interest) for which the color strength of the image displayed on the CRT 10 is to be changed, and converts the image data of the pixel of interest into image data.
- RAM power Read The color density of the pixel of interest is a numerical value corresponding to the sRGB color space on the CRT 10 screen.
- the control unit 22 determines the L * a * b * color as a uniform color space. It is configured to perform image processing using the space, and the color density of the sRGB color space is changed to the L * a * b * color space.
- the point S (Ls, as, bs) corresponding to the color density of the target pixel is defined in the L * a * b * color space (see FIG. 4).
- the conversion between the color density in the sRGB color space and the color density in the L * a * b * color space is appropriately performed based on a predetermined conversion formula or a conversion formula determined experimentally.
- the color density change process is a process of changing the point S corresponding to the color density of the target pixel in the L * a * b * color space to change the color density of the target pixel.
- the color density conversion processing is executed in response to a color density change instruction transmitted from the operation unit 11.
- the displacement of the point S corresponding to the color density of the target pixel in the L * a * b * color space is a force performed based on the LUT. It is also possible.
- the color density change processing is performed based on the LUT.
- each color density change instruction instead of using an existing LUT, is defined with a unit change amount for each of the lightness component of the color density and a predetermined input value of the color component. LUTs are created based on the defined unit change amount.
- the specified color density change instruction is ⁇ + Yj, ⁇ , “+ M”, “1M”, “+ C”, and “1C”. Instructing to change each color density.
- the LUTs for the a * component and the b * component The 45 ° straight line indicated by the line is created as a translated straight line (that is, a linear function), and the unit change amount for the a * component and the b * component indicates the distance of the translation. Numeric values are defined one by one.
- the L * The unit change amount of each component of b * can be set or changed for each color density change instruction.
- the control unit 22 determines a point S (Ls, as) corresponding to the color density of the target pixel based on the LUT as shown in FIG. , bs) to the point T (Lt, at, bt) to change the color density of the target pixel.
- the LUT is configured such that the amount of change in the displacement of the a * component and the displacement of the b * component is increased or decreased by a fixed value from the input value, respectively (see FIG. 5 (B) and FIG. 5 (C)), and in FIG. 6, when the vector directed to the point S force point T is vector M, the a * component and b * component of the vector M have constant values. Therefore, in the color density change processing, the color density of each pixel is kept at least in the a * component and the component, that is, the direction of the change is maintained in a constant direction with respect to the color component.
- each LUT has a converted output value of L * It is configured to allow conversion to a value larger than the maximum value or smaller than the minimum value of each component of b *, and does not involve clipping! /.
- the power that can define the vector Y and the vector C indicating the unit change amount is “+ Y” processing and As shown in FIG. 7, the “+ C” processing is performed as shown in FIG. 7, in which the total sum of the unit changes in the a * component and the b * component of the vector Y and the vector C and the solid vector M is 0, that is, the vector The processing is determined so that the sum becomes a vector on the L * axis, and the unit change instruction for each color.
- the vectors indicating the unit change amount of each process of “ ⁇ Y“ ⁇ ”and C” are the vectors Y and “Y” indicating the unit change amount of each process of “+ Y” “+ ⁇ ” and “+ C”, respectively. It is represented as a vector having the same length in the opposite direction to the vector ⁇ and the vector C, and has the same relationship as that shown in FIG. 7, and similarly, the unit change instruction for each color.
- the vectors ⁇ ⁇ ⁇ ⁇ , ⁇ , and C described here are vectors defined in the L * a * b * color space as described above, and are used in an inkjet recording apparatus or the like. It differs from the basic vector in the YMC color space as the color space used.
- the “+ D” button or the “ ⁇ 0” button of the operation unit 11 is pressed to perform “+ DJ processing (or“ ⁇ D ”processing).
- the brightness of the image on the screen of the CRT 10 can be darkened (or brightened) as a whole.
- the unit change amount of the minimum value 0, the maximum value 100, and the intermediate value 50 of the input value is defined only for the L * component, and the unit variation for the a * component and the b * component is defined.
- the change amount is 0.
- the ⁇ + T '' and ⁇ --T '' processes which increase or decrease the contrast of the entire image, also use the L * component in proportion to the distance from the fixed brightness in the L * axis direction, based on the fixed brightness.
- the unit change amount of the minimum value 0, the maximum value 100 and the intermediate value 50 of the input value is defined only for the L * component.
- control unit 22 sets L *, L * for each input change instruction. Add all the unit change amounts for each component of b *, and calculate L *, It is configured to create a LUT for each component of b *.
- the LUT of the L * component is determined by calculating the exponential function that passes through the sum of the unit changes at the input values 0, 50, and 100, respectively.
- the LUT is created by translating the 45 ° straight line indicated by the dashed line in Fig. 5 (B) and Fig. 5 (C), for example, by the sum of the unit change amounts. .
- the control unit 22 is configured to read a table of the regulation process as shown in FIG. 8 from the ROM, load the table on the RAM, and perform regulation based on the table.
- the changes in the a * and b * components are reduced by the same regulation value ⁇ . Therefore, the directionality of the change in the color density of each pixel in the above-described color density change processing is kept constant.
- the regulation may be configured to be performed in accordance with the lightness L, or to be performed in accordance with the hue H described later, or may be configured to be performed in accordance with both. It is.
- the lightness L, chroma C, and hue H of a pixel in the L * a * b * color space will be described.
- the coordinates of a point in the L * a * b * color space corresponding to the color density of one pixel in the image displayed on the screen of the CRT10 are generally expressed as (L *, a *, b *)
- the brightness L, saturation, and hue H of the pixel are expressed as follows.
- the hue ⁇ ⁇ is the a * axial force when the point S corresponding to the pixel is projected on the a * b * plane. This corresponds to the angle ⁇ (see FIGS. 9 (A) and 9 (B)).
- the L * a * b * color space is a set of points where the angle ⁇ from the a * axis when projected on the a * b * plane is constant, that is, as shown in Fig. 9 (A) All points on the LC plane as shown in Fig. 3 are formed to have the same hue ⁇ .
- the hue ⁇ ⁇ can take a value of 0 ° or more and less than 360 °.
- the CRT 10 cannot express all points in the L * a * b * color space in its lightness L, saturation C, and hue ⁇ . Only points within can be expressed.
- the image in the L * a * b * color space that can be displayed on the screen of the CRT 10 is The elementary color density area is called a defined color gamut, and this defined color gamut is represented on the LC plane as an area R indicated by oblique lines in FIG.
- a table of maximum values that can be taken by the saturation C corresponding to each lightness L in a certain hue H is stored in all the hue H Are defined and stored.
- the table showing the defined color gamut is such that the maximum value of the saturation C (that is, the boundary value of the definition area R) for 101 lightnesses L from 0 to 100 on one LC plane is defined as Each is assigned and defined for each of the 360 angles H (ie, hue H) from 0 ° to 359 °.
- the determination process is a process for determining whether or not the target pixel is within the defined color gamut.
- control unit 22 determines in this determination process that the target pixel after the color density change processing is within the defined color gamut, the control unit 22 stores the color density data of the target pixel after the color density change processing in the RAM.
- the gamut compression process is a process in which a pixel of interest outside the defined gamut is displaced within the defined gamut on the same LC plane while its hue is kept constant.
- the area outside the defined color gamut on the LC plane is The image data is divided, and color gamut compression processing is performed in accordance with the color gamut compression rules determined for each region.
- the maximum saturation point Nl (Cnl, Lnl) and the brightness on the defined gamut R A line connecting the maximum saturation point N1 and the convergence point N2 with a point N2 (Cn2, Ln2) (hereinafter referred to as a convergence point) having the same Lnl and shifted by a fixed value to the low saturation side on the defined color gamut R.
- a straight line that forms the angle of 0 1 on the high brightness side with the convergence point N2 as the starting point is defined as a straight line 1 (first straight line), and the angle of angle ⁇ 2 on the low brightness side with the convergence point N 2 as the starting point.
- a method is used in which the defined out-of-gamut region is divided into three by dividing the out-of-defined-gamut region by the straight line 1 and the straight line 2 as a straight line 2 (second straight line).
- the out-of-definition color gamut area on the lightness side higher than straight line 1 is the first area (the first out-of-definition color gamut area).
- the outside of the defined gamut on the degree side is the second area (outside the second defined gamut), and the outside of the defined gamut on the lightness side lower than the straight line 2 is the third area (outside the third defined gamut).
- the distance between the maximum saturation point N1 and the convergence point N2 and the values of the angle 01 and the angle 02 can be set as appropriate, and the convergence point N2 has the same brightness as the maximum saturation point N1. It can be set arbitrarily within the defined color gamut. Further, it is also possible to set the convergence points ⁇ 2, ⁇ 1 value and 02 value for each hue H (ie, for each angle H in FIG. 7).
- control unit 22 determines which region is outside the defined color gamut to which the pixel of interest belongs, and according to the compression rule defined in each defined color gamut region. Performs color gamut compression.
- the rule of the color gamut compression in the region outside the defined color gamut is such that when a point corresponding to the color density of the pixel of interest after the color density change processing exists in the first area, that point is determined. Displaced in the direction parallel to line 1 (ie, at an angle ⁇ 1), displaced by force toward convergence point N2 when in the second region, and parallel to line 2 when in the third region In other words, they are displaced in different directions (that is, at an angle of ⁇ 2) and are compressed to points on the defined gamut boundaries (see FIG. 14).
- the points on the defined gamut boundary to be compressed are configured to be calculated and obtained by the control unit 22 based on the table.
- a point corresponding to the color density of the target pixel is located on the boundary of the defined color gamut.
- the saturation may become zero.
- the color gamut is compressed on the boundary where the saturation is 0 and the brightness is the closest.
- the saturation is 0 and the lightness is the maximum value (in this case, If the point in the third area is displaced by ⁇ 2 and intersects with the lightness axis, the point of saturation is 0 and the lightness is the minimum value (0 in this case).
- the difference between the lightness Lt of the point T before the color gamut compression process and the lightness Lul of the point U1 after the color gamut compression process May increase, and the image may feel uncomfortable.
- the maximum lightness displacement amount A Lmax is set, and the absolute value of the difference between the lightness Lt before the color gamut compression processing and the lightness Lul after the expected color gamut compression processing is set. If the value exceeds the maximum lightness change amount A Lmax, the color gamut is compressed to a point on the defined color gamut boundary where the lightness change amount is the maximum lightness change amount A Lmax.
- control unit 22 stores the color density data of the pixel of interest after the processing in the RAM.
- FIG. 17 is a flowchart showing the procedure of the image processing method.
- control unit 22 of the image processing apparatus 1 stores the image data of the image specified according to the specification information from the operation unit 11.
- the image read out from the means 23 is displayed on the CRT 10.
- the control unit 22 sends an instruction to change the color density that has already been executed. If present, the sum of the unit change amounts of the L * component, a * component, and b * component of each process that has already been added is read out from the RAM force, and the L * component, a * The sum of the unit changes of each of the L *, a *, and b * components is calculated based on the sum of the unit changes by adding the unit changes of the components and the b * components, respectively (step S1). Create an LUT (step S2).
- the sum of the unit changes of the newly added L * and ab * components is stored in the RAM.
- the ability to determine the amount of change in the color density of the pixel of interest based on each LUT At this time, in the present embodiment, the amount of change in the a * and b * components of the pixel of interest is stored in RAM.
- the regulation is performed with reference to the regulation value a corresponding to the lightness L shown in FIG. 8 (step S3).
- a color density change process is executed based on the amounts of change of the L *, a *, and b * components thus obtained (step S4).
- the LUTs for the displacements of the a * component and the b * component used by the control unit 22 for changing the color density add a constant value to the input value (see FIG. 5B) or decrease the input value (see FIG. 5B).
- the vector M of the color density change in the operation of “+ M” from point S to point T in FIG. 6 is projected on the a * b * plane. As shown in the figure, the vector M points in the same direction at all points on the a * b * plane.
- the control unit 22 reads out a table showing the defined color gamut for the hue Ht of the point T corresponding to the color density of the target pixel after the color density change processing, and executes the determination processing ( Step S5).
- the control unit 22 determines in this determination process that the target pixel after the color density change process is within the defined color gamut
- the control unit 22 stores the color density data of the target pixel after the color density change process in the RAM, and stores the data in the RAM.
- the image processing for the pixel of interest is completed, the next pixel on the image of the CRT 10 is selected, and the above-described processing procedure is repeated.
- control unit 22 determines that the target pixel after the color density change processing is out of the defined color gamut in the above-described determination processing, the control unit 22 goes out of the defined color gamut on the LC plane as described above.
- the region into which the pixel of interest belongs is determined by dividing the region into three (Step S6), and the gamut compression process is performed in accordance with the gamut compression rules defined for each region (Steps S7 to S9). .
- the control unit 22 stores the color density data of the pixel of interest after the color gamut compression processing in the RAM, and stores the image for the pixel of interest.
- the image processing is completed, the next pixel is selected as the image power on the screen of the CRT 10, and the above-mentioned processing procedure is repeated.
- the control unit 22 controls the above-described color density for all the pixels of the image on the screen of the CRT 10.
- the change processing, the determination processing, and the color gamut compression processing are completed, the next image processing is accepted, and an image processing instruction from the operation unit 11 is waited.
- an instruction for the next image processing is input from the operation unit 11, processing is performed according to the above-described procedure.
- data on all pixels of the image stored in the RAM is stored in the data storage unit 23 as image data of the image. At that time, the image data may be stored as data different from the original image data, or may be configured to be overwritten and stored on the original image data.
- the control unit 22 stores the image data stored in the RAM in the data storage unit 23, and simultaneously transmits the image data to the exposure processing unit 13. .
- control unit 22 processes the image data on the RAM without displaying the image on the CRT 10 and processes the image.
- similar operations are performed when color correction, density correction, and the like are automatically corrected.
- a color density change instruction (for example, “+ M” processing) is performed based on the unit change amount.
- the LUT which is the standard for color density change processing and does not involve clipping processing, is created by dividing the lightness component of color density into the a * and b * components of color components, and based on those, Since the lightness component and the color component are changed separately, the lightness component and the color component of the color density can be changed independently of each other. It is possible to change the color density with the same direction.
- the LUT for the L * component is create Using the exponential function used to create the LUTs for the a * and b * components, and the color density of the pixel of interest without LUT creation It is also possible to obtain the amount directly by calculation, which improves the calculation accuracy.
- calculation is performed only on the grid points of the 3D LUT or changes based on the LUT are performed, and points around the grid points are subjected to color density change processing and the like in a state attached to the grid points.
- the present invention can be applied to image processing using a dimensional LUT. In this case, if the processing speed for a large image is increased, the effect is improved.
- L *, L *, A new LUT is created or calculated by adding the unit change amount for each component of b *. Therefore, after performing a certain color density change process (for example, “+ M” process) and then another color density change process (for example, “+0” process), the reverse color density change process (“ If the “1M” process and the “1D” process) are performed, the inverse processes are necessarily canceled out, and the sum of the unit change amounts becomes 0 in all cases, and the image can be returned to the initial image.
- a certain color density change process for example, “+ M” process
- another color density change process for example, “+0” process
- the reverse color density change process (“ If the “1M” process and the “1D” process) are performed, the inverse processes are necessarily canceled out, and the sum of the unit change amounts becomes 0 in all cases, and the image can be returned to the initial image.
- the same gamut compression processing can be used to execute the same LC plane. Since the gamut is compressed within the defined gamut by displacing it in the plane of the same hue, that is, in the defined gamut, the hue of the pixel becomes unnatural due to the uniform displacement effect in the L * a * b * color space described above. Can be reliably prevented.
- the color density of the pixel after the color density change processing is more likely to fall outside the defined color gamut.
- the color density of the target pixel can easily fall within the defined color gamut, and the trouble of performing the color gamut compression process can be easily omitted. In addition, it is possible to prevent unnecessary highlight coloring and a decrease in color discrimination at high saturation. Furthermore, in this regulation process, as described above, the hue is unnaturally changed in order to regulate the color density of the target pixel in the color density change process while maintaining the directionality of the change. Thus, the effect of enabling the operator to perform the expected color reproduction without performing the above operation is maintained.
- the point S in the L * a * b * color space corresponding to the color density that goes out of the defined color gamut by performing the above-described regulation process has a smaller force S.
- the processed pixels can be displayed on the screen of the CRT 10. Also, since the color gamut compression processing is performed on the LC plane where the hue H is constant, the hue of the pixel does not change by these processings, and the color reproduction assumed by the operator is also performed. Is guaranteed.
- the out-of-defined-gamut area on the LC plane is divided into three parts, and the points are displaced in the first area in parallel with the straight line 1 (first straight line). Compressed to a point on the defined gamut boundary, and displaced toward the convergence point N2 corresponding to the intersection of line 1 and line 2 (second line) in the second region, and compressed to a point on the defined gamut boundary.
- the third area by adopting a rule of displacing parallel to the straight line 2 and compressing it to points on the boundary of the defined gamut, for example, all points in a certain area outside the defined gamut can be defined.
- the CRT10 screen after color gamut compression will not be compressed to a specific point on the boundary, nor will there be any point on the boundary of the defined gamut that will not be compressed from any of the defined gamut regions.
- the gradation of the upper image can be made very smooth without any unnaturalness.
- a convergence point ⁇ 2 is set on the lightness axis, and the color density change processing for increasing the lightness of the entire image ( ⁇ )
- the image processing ( ⁇ ) Points S1 and S2 are color gamut compressed to points Ul and U2 via points Tl and ⁇ 2, respectively
- points S3 and S4 are points U3 via points T3 and ⁇ 4 respectively.
- the gamut is compressed to U4.
- the operation unit 11 shown in FIG. 2 is configured to add the unit change amount corresponding to each color density change instruction by the number of times of pressing a button such as “+ Y”.
- a button such as “+ Y”.
- a slide bar is displayed on the screen of the CRT 11 in the form of a wizard. It is also possible to input a numerical value corresponding to the number of times the button is pressed on the operation unit 11 of FIG. Further, as shown in FIG. 23, it is also possible to configure to input a numerical value more finely according to the type of the film or the medium from which the image is read.
- the operation unit 11 of the slide bar system in FIG. 22 or the operation unit 11 of FIG. 23 for directly inputting a numerical value can input not only an integer value but also a decimal value, so that more precise It can also be configured to perform image processing.
- the image information is read from a film, a medium, or a print to create image data, and the image data is subjected to image processing to change the color density, and the image data is converted into a hue.
- the expected color reproduction can be performed without any problem.
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JP2004159372A JP2005339343A (ja) | 2004-05-28 | 2004-05-28 | 画像処理方法、画像処理プログラムおよび画像処理装置 |
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Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07262347A (ja) * | 1994-03-18 | 1995-10-13 | Fujitsu Ltd | 画像処理装置 |
JPH11191846A (ja) * | 1997-12-25 | 1999-07-13 | Canon Inc | 画像処理装置、方法および記録媒体 |
JPH11341264A (ja) * | 1998-05-29 | 1999-12-10 | Canon Inc | モザイク画像生成方法、記録媒体 |
JP2000165692A (ja) * | 1998-11-30 | 2000-06-16 | Fujitsu Ltd | カラーデータ変換方法 |
JP2000278546A (ja) * | 1999-01-22 | 2000-10-06 | Sony Corp | 画像処理装置及び画像処理方法、色域変換テーブル作成装置及び色域変換テーブル作成方法、画像処理プログラムを記録した記録媒体、並びに色域変換テーブル作成プログラムを記録した記録媒体 |
JP2001028694A (ja) * | 1999-05-07 | 2001-01-30 | Matsushita Research Institute Tokyo Inc | 画像処理装置及び画像処理方法 |
JP2002027263A (ja) * | 2000-07-04 | 2002-01-25 | Matsushita Electric Ind Co Ltd | 画像処理方法 |
JP2003110868A (ja) * | 2001-10-01 | 2003-04-11 | Canon Inc | 画像処理方法、画像処理装置、記憶媒体及びプログラム |
-
2005
- 2005-05-17 WO PCT/JP2005/008972 patent/WO2005117412A1/ja active Application Filing
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07262347A (ja) * | 1994-03-18 | 1995-10-13 | Fujitsu Ltd | 画像処理装置 |
JPH11191846A (ja) * | 1997-12-25 | 1999-07-13 | Canon Inc | 画像処理装置、方法および記録媒体 |
JPH11341264A (ja) * | 1998-05-29 | 1999-12-10 | Canon Inc | モザイク画像生成方法、記録媒体 |
JP2000165692A (ja) * | 1998-11-30 | 2000-06-16 | Fujitsu Ltd | カラーデータ変換方法 |
JP2000278546A (ja) * | 1999-01-22 | 2000-10-06 | Sony Corp | 画像処理装置及び画像処理方法、色域変換テーブル作成装置及び色域変換テーブル作成方法、画像処理プログラムを記録した記録媒体、並びに色域変換テーブル作成プログラムを記録した記録媒体 |
JP2001028694A (ja) * | 1999-05-07 | 2001-01-30 | Matsushita Research Institute Tokyo Inc | 画像処理装置及び画像処理方法 |
JP2002027263A (ja) * | 2000-07-04 | 2002-01-25 | Matsushita Electric Ind Co Ltd | 画像処理方法 |
JP2003110868A (ja) * | 2001-10-01 | 2003-04-11 | Canon Inc | 画像処理方法、画像処理装置、記憶媒体及びプログラム |
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