Patent Description:
The recent advancement of image processing techniques has made it possible to easily take pictures with a bokeh effect, which are generally called portraits, using a digital camera or a smartphone without using an expensive telescopic single focus lens in particular.

Sublimation thermal transfer type image forming apparatuses capable of photographically printing an image captured by a digital still camera or a smartphone have been known. The sublimation thermal transfer type refers to a method of pressing a heated thermal head against an ink ribbon to sublimate ink from solid to gas and making the ink adhere to photographic paper. Inks are arranged on the ink ribbon in the form of yellow (Y), magenta (M), and cyan (C) sublimation dye layers and an overcoat (OC) layer. An image formed using the YMC sublimation dye layers (the YMC sublimation dye inks) is protected by the colorless transparent OC layer (the transparent OC ink) to provide a highly durable, waterproof finish.

The OC layer not only has the function of protecting a photographic print product, but also is used for various applications. Special effects can be obtained by changing the amount of heat to be applied to control the surface shape of the protective layer and change reflectance.

<CIT> discusses a technique for recording user-requested information in a photographic print product by changing the transfer amount of the OC ink. Text and graphic information can be expressed by using the colorless transparent OC layer. Printing using the transparent OC layer is less discernible and thus has the advantage of being less likely to affect the photographically printed image therebelow.

It is desirable that an image captured as a portrait should provide a beautiful bokeh effect so that the main subject such as a person or a still object appears clearly and sharply and the background is out of focus.

<CIT> discloses a printing system and method in which the amount of fixer fluid is varied in different areas of a printed product such that the areal density of fixer fluid in a boundary region of the print area is different that the areal density in an interior region of the print area.

The present invention is directed to enhancing an effect of a sharply contrasted picture such as a portrait to obtain a more expressive picture by changing the transfer amount of transparent protective ink, such as an overcoat (OC) ink, to control surface properties. In other words, the present invention is directed to providing a print control apparatus and a print control method capable of printing that provides different surface properties for the subject, such as a person or a still object, and the surrounding background by transferring transparent protective ink, such as an OC ink, differently to control the surface properties.

According to a first aspect of the present invention, there is provided a print control apparatus as specified in claims <NUM> to <NUM>. According to a second aspect of the present invention, there is provided a print control method as specified in claim <NUM>. According to a third aspect of the present invention, there is provided a computer program as specified in claim <NUM>.

An aspect of the present invention provides a print control apparatus and a print control method capable of printing that provides different surface properties for the subject, such as a person or a still object, and the surrounding background by transferring transparent protective ink, such as an OC ink, differently to control the surface properties.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In the following description, "printing" refers to an entire series of processes and operations from photographic printing based on a print instruction from a user to printout discharge. "Photographic printing" refers to, among the series of processes and operations, the process and operation for forming an image on a substrate such as a recording sheet by thermally transferring a transfer material (an ink or an overcoat) applied to an ink sheet (an ink ribbon) onto the recording sheet.

<FIG> is a block diagram of a thermal transfer type printer (a printing apparatus or a print control apparatus) <NUM> according to an embodiment of the present invention. A central processing unit (CPU) <NUM> performs system control and calculation processing of the printer <NUM>. A flash read-only memory (ROM) <NUM> stores a system control program of the printer <NUM>. The CPU <NUM> reads a program from the flash ROM <NUM> and controls various components based on the read program. A synchronous dynamic random access memory (SDRAM) <NUM> temporarily stores image data and is used for data processing operations. The CPU <NUM>, the flash ROM <NUM>, and the SDRAM <NUM> constitute a main control unit <NUM> that mainly processes various types of control of the printer <NUM>. Functions and processing of the printer <NUM> to be described below are implemented by the CPU <NUM> reading a program stored in the flash ROM <NUM> and executing the program. An image processing unit <NUM> performs image processing on image data transmitted from a digital camera or a portable terminal, and image data read from a storage medium <NUM>. The image processing unit <NUM> performs various types of image processing on image data and generates, based on the processed image data, print data for photographic printing. Examples of the image processing include decompression processing on compressed image data, resize processing based on paper to be used, and image correction processing.

The image processing unit <NUM> according to the present embodiment is characterized by performing processing related to image data generation for an overcoat (OC) layer. The printer <NUM> according to the present embodiment particularly has a special mode called main subject emphasis mode. In a case where the main subject emphasis mode is selected, the image processing unit <NUM> selects a specific range in the image data and performs contour extraction in the specific range. Based on a result of the extraction, the image processing unit <NUM> generates photographic print data to be applied to the OC layer. Details thereof will be described below with reference to <FIG>.

As another example, the processing of the image processing unit <NUM> may be performed by the main control unit <NUM> instead of the image processing unit <NUM>, or the image processing unit <NUM> and the main control unit <NUM> may perform the processing together.

A thermal head control unit <NUM> converts the print data generated by the image processing unit <NUM> into an electrical signal and outputs the electrical signal to a thermal head <NUM>. The thermal head <NUM> transforms the electrical signal into thermal energy and transfers dye from an ink ribbon <NUM> (see <FIG>) to a sheet.

A head temperature sensor <NUM> measures a temperature of the thermal head <NUM>. An ambient temperature sensor <NUM> measures an ambient temperature in the printer <NUM>. A head position sensor <NUM> detects a position of the thermal head <NUM>, such as a pressing position or a retracted position. A sheet detection sensor <NUM> detects a position of a sheet. An ink ribbon detection sensor <NUM> detects information about the ink ribbon <NUM>. A marker detection sensor <NUM> detects markers disposed on the ink ribbon <NUM>.

A motor driver unit <NUM> controls motors. A head position drive motor <NUM> is used to drive the thermal head <NUM> to the pressing position for performing the photographic printing or the retracted position for replacing an ink ribbon cassette <NUM> (see <FIG>) or conveying a sheet. A sheet conveyance motor <NUM> is used to convey the sheet. The main control unit <NUM> issues commands to the motor driver unit <NUM> to control driving of the head position drive motor <NUM> and the sheet conveyance motor <NUM>, based on sensor information from the foregoing various sensors and information programmed in advance.

A display unit <NUM> displays an image stored in the storage medium <NUM> and an operation menu of the printer <NUM>. An example of the display unit <NUM> is a liquid crystal display (LCD). An operation unit <NUM> is used to input instructions from the user. A communication unit <NUM> controls communication with an external device, such as a digital camera, connected to the printer <NUM>. A memory controller <NUM> reads or writes image data from or to the storage medium <NUM> attached to the printer <NUM>. The storage medium <NUM> stores image data and is detachably attached to the printer <NUM>.

<FIG> is an external view of the printer <NUM> and the ink ribbon cassette <NUM>. On a side of a printer main body <NUM>, an ink ribbon cassette slot <NUM> into which the ink ribbon cassette <NUM> can be inserted is provided, and the ink ribbon cassette <NUM> is attachable and detachable in a direction indicated by an arrow A. On a front side of the printer main body <NUM>, a sheet tray slot <NUM> into which a sheet tray <NUM> can be inserted is provided. The sheet tray <NUM> is attachable and detachable in a direction indicated by an arrow B.

The display unit <NUM> and the operation unit <NUM> are disposed on a top side of the printer main body <NUM>. The user can view images and image processing information displayed on the display unit <NUM> and select an image to be photographically printed by operating the operation unit <NUM>. In response to the instruction from the user, the printer <NUM> can process the image as appropriate and photographically print the image.

<FIG> is a plan view of the ink ribbon <NUM>. The ink ribbon <NUM> includes three color ink layers, namely, a yellow (Y) layer <NUM>, a magenta (M) layer <NUM>, and a cyan (C) layer <NUM> applied to a base film surface. The plurality of color ink layers (the Y layer <NUM>, the M layer <NUM>, and the C layer <NUM>) is arranged on the ink ribbon <NUM>. The ink ribbon <NUM> further includes an OC layer <NUM> applied to the base film surface, following the Y layer <NUM>, the M layer <NUM>, and the C layer <NUM>. The OC layer <NUM> is formed of transparent protective ink for protecting an image printed on a sheet using the color inks of the Y layer <NUM>, the M layer <NUM>, and the C layer <NUM>. Transferring the protective ink of the OC layer <NUM> onto the image can protect the image and provide a highly durable, waterproof finish.

Markers <NUM> to <NUM> for layer delimitation and cueing are applied between the YMC layers <NUM> to <NUM>, between the C layer <NUM> and the OC layer <NUM>, and between the OC layer <NUM> and the Y layer <NUM>. The Y layer <NUM> at the beginning of each ink group is preceded by the two markers <NUM> and <NUM>. Each of the other boundaries between the layers is provided with one of the markers <NUM> to <NUM>.

When the photographic printing is started, the main control unit <NUM> first controls take-up driving of the ink ribbon <NUM> to detect the Y layer <NUM> at the beginning of the ink group. After detecting the marker <NUM>, the main control unit <NUM> performs control to further take up the ink ribbon <NUM> to a position where the second marker (the marker <NUM>) is supposed to be detected. When detecting the marker <NUM>, the main control unit <NUM> determines the beginning of the ink group.

The marker detection sensor <NUM> according to the present embodiment is a reflection infrared sensor. The dyes in the YMC layers <NUM>, <NUM>, and <NUM> for normal use and the coating agent in the OC layer <NUM> do not absorb infrared radiation having an emission wavelength of approximately <NUM> to <NUM>. Since the infrared radiation transmits through the ink sheet (the ink ribbon <NUM>) regardless of hue, use of infrared blocking markers enables detection of the boundaries between the ink portions and the markers. The markers can be formed by containing an infrared blocking material.

<FIG> are sectional side views of the printer <NUM>. A mechanical configuration of the printer <NUM> and basic operations related to the photographic printing will be described with reference to <FIG> illustrates the printer <NUM> in a standby state. <FIG> illustrates the printer <NUM> during sheet feeding. <FIG> illustrates the printer <NUM> before start of the photographic printing. <FIG> illustrates the printer <NUM> during the photographic printing. <FIG> illustrates the printer <NUM> during sheet discharge. The thermal head <NUM> is illustrated in <FIG>. A thermal head support arm <NUM>, a heat radiation plate <NUM>, and a platen roller <NUM> are also illustrated in <FIG>. The thermal head support arm <NUM> is rotatably supported about a rotation shaft <NUM>.

The thermal head <NUM> is fixed to the thermal head support arm <NUM>. Accordingly, the thermal head <NUM> is movable from a first retracted position illustrated in <FIG> to a second retracted position illustrated in <FIG> and from the second retracted position to a pressing position illustrated in <FIG>, so that the thermal head <NUM> and the platen roller <NUM> can produce a pressure contact force therebetween. The heat radiation plate <NUM> is attached to the thermal head <NUM> and is configured to transfer heat generated by the thermal head <NUM> to the heat radiation plate <NUM>. The platen roller <NUM> is rotatably disposed on the printer main body <NUM> and is configured to rotate with the conveyance of each sheet <NUM>.

A conveyance roller <NUM> is configured to be driven to rotate by a sheet conveyance motor (not illustrated). A driven roller <NUM> is opposed to the conveyance roller <NUM> and is configured to rotate by the rotation of the conveyance roller <NUM>. A sheet feed roller <NUM> is configured to be driven to rotate by a sheet feed drive motor (not illustrated). A sheet discharge roller <NUM> is a driven roller opposed to the sheet feed roller <NUM> and is configured to rotate by the rotation of the sheet feed roller <NUM>.

A reflective sticker <NUM> is attached to a case <NUM> of the ink ribbon cassette <NUM> at a position opposed to the marker detection sensor <NUM> where the ink ribbon <NUM> is between the marker detection sensor <NUM> and the reflective sticker <NUM>. Infrared radiation from the marker detection sensor <NUM> transmits through the ink ribbon <NUM>, is reflected by the reflective sticker <NUM>, transmits through the ink ribbon <NUM> again, and is incident on a light receiving portion of the marker detection sensor <NUM>.

A sheet guide <NUM> is supported so that, during sheet feeding, the sheet guide <NUM> is raised by the sheet <NUM> and is rotatable from a position illustrated in <FIG> to a position illustrated in <FIG>. The sheet guide <NUM> is constantly urged downward and located at the position illustrated in <FIG> except during sheet feeding. A pressing plate <NUM> is driven to rotate by a driving source (not illustrated) and is configured to be rotatable from a position illustrated in <FIG> to a position illustrated in <FIG>. When the pressing plate <NUM> is driven to the position illustrated in <FIG>, a lift plate <NUM> rotatably supported inside the sheet tray <NUM> is lifted up to press the uppermost one of the sheets <NUM> stored in the sheet tray <NUM> against the sheet feed roller <NUM>. This enables sheet feeding. The sheet detection sensor <NUM> is provided below the sheet guide <NUM>.

<FIG> is a flowchart illustrating normal photographic print processing by the printer <NUM>. The normal photographic print processing refers to processing in which information specified as a photographic print target is printed and accompanying information is not printed. An image specified as the photographic print target, i.e., an image to be printed will be hereinafter referred to as a target image. When the ink ribbon cassette <NUM> is inserted into the ink ribbon cassette slot <NUM> of the printer main body <NUM> as illustrated in <FIG>, a rotation restriction unit (not illustrated) between a supply bobbin <NUM> and a take-up bobbin <NUM> is disengaged from the case <NUM> of the ink ribbon cassette <NUM>. This enables the supply bobbin <NUM> and the take-up bobbin <NUM> to be driven to rotate by a rotation drive mechanism provided in the printer main body <NUM>. Inserting the sheet tray <NUM> into the sheet tray slot <NUM> of the printer main body <NUM> enables feeding of the sheets <NUM>. When the main control unit <NUM> receives a photographic print instruction from the user via the operation unit <NUM>, in a state of the ink ribbon cassette <NUM> and the sheet tray <NUM> being inserted and in a state of readiness for the photographic printing, the main control unit <NUM> starts the normal photographic print processing. In step S601, the main control unit <NUM> performs control to bring the sheets <NUM> into contact with the sheet feed roller <NUM>. As illustrated in <FIG>, the pressing plate <NUM> is driven to rotate by the driving source (not illustrated) under control of the main control unit <NUM>, so that the sheets <NUM> stored in the sheet tray <NUM> are brought into contact with the sheet feed roller <NUM>. In step S602, the main control unit <NUM> controls the sheet feed driving source (not illustrated) to drive the sheet feed roller <NUM> to rotate, so that the sheets <NUM> are fed from the sheet tray <NUM> one by one. At this time, the leading edges of the sheets <NUM> come into contact with a sheet separation portion <NUM>, so that the printer <NUM> can separate the uppermost sheet from the sheets <NUM> and feed the uppermost sheet. The sheet <NUM> is conveyed while pushing up the sheet guide <NUM>. When the leading edge of the sheet <NUM> reaches a position above the sheet detection sensor <NUM>, the sheet <NUM> is further conveyed by a predetermined amount from that position, and the main control unit <NUM> determines that the leading edge of the sheet <NUM> is conveyed to a nip position between the conveyance roller <NUM> and the driven roller <NUM>. When the sheet <NUM> is conveyed to the nip position between the conveyance roller <NUM> and the driven roller <NUM> illustrated in <FIG>, the conveyance roller <NUM> is driven to rotate by rotation of the sheet conveyance motor (not illustrated), so that the sheet <NUM> is further conveyed. At this time, the main control unit <NUM> drives the pressing plate <NUM> to move away from the sheet tray <NUM>, so that the sheets <NUM> are separated from the sheet feed roller <NUM>. From that point on, the main control unit <NUM> switches the driving source for conveying the sheet <NUM> to the conveyance roller <NUM>. The main control unit <NUM> further drives the conveyance roller <NUM>, so that the sheet <NUM> is conveyed in a direction indicated by an arrow G in <FIG> so as to pass between the thermal head <NUM> and the platen roller <NUM>. When the sheet <NUM> is conveyed to a photographic printing start position illustrated in <FIG>, the main control unit <NUM> moves the thermal head <NUM> from the first retracted position illustrated in <FIG> to the second retracted position illustrated in <FIG>. When the thermal head <NUM> has been moved to the second retracted position, a ribbon drive system for rotatably driving the take-up bobbin <NUM> of the ink ribbon <NUM> is switched to be driven by a cam (not illustrated). The main control unit <NUM> then rotates the take-up bobbin <NUM> to draw the ink ribbon <NUM> from the supply bobbin <NUM> in the ink ribbon cassette <NUM>.

In step S603, the main control unit <NUM> controls movement of the ink ribbon <NUM>. More specifically, the main control unit <NUM> starts taking up the ink ribbon <NUM> first. After the start of taking up the ink ribbon <NUM>, the main control unit <NUM> continues taking up the ink ribbon <NUM> until the marker detection sensor <NUM> detects the markers <NUM> and <NUM> illustrated in <FIG> in this order. At the time when the markers <NUM> and <NUM> are detected in this order, the main control unit <NUM> stops the take-up operation of the ink ribbon <NUM>. By stopping the ink ribbon <NUM> at the time when the marker <NUM> is detected, the photographic printing start position of the Y layer <NUM> of the ink ribbon <NUM> is aligned with a position opposing the thermal head <NUM>. In step S604, to perform desired color photographic printing, the main control unit <NUM> starts Y photographic printing first. More specifically, the main control unit <NUM> controls the driving source (not illustrated) to rotate the thermal head support arm <NUM> and stop the thermal head <NUM> at the pressing position illustrated in <FIG>. Accordingly, the main control unit <NUM> performs control so that the ink ribbon <NUM> and the sheet <NUM> are in pressure contact with each other between the thermal head <NUM> and the platen roller <NUM>. In step S605, the main control unit <NUM> controls Y photographic printing corresponding to the target image. More specifically, while controlling the conveyance roller <NUM> to convey the sheet <NUM> in a direction indicated by an arrow F in <FIG>, the main control unit <NUM> causes the heating element of the thermal head <NUM> to generate heat based on a photographic print signal, thereby thermally transferring the dye of the Y layer <NUM> to the sheet <NUM>. At this time, the take-up bobbin <NUM> is driven to rotate by the driving source (not illustrated), so that the ink ribbon <NUM> is conveyed in the direction indicated by the arrow F in <FIG> at substantially the same conveyance speed as that of the sheet <NUM>. The ink ribbon <NUM> is conveyed while being in contact with a shaft <NUM> rotatably supported in the ink ribbon cassette <NUM>. This reduces the conveyance resistance of the ink ribbon <NUM> and prevents a photographic printing failure due to wrinkles caused by defective conveyance of the ink ribbon <NUM>. After the Y photographic printing is completed, in step S606, the main control unit <NUM> rotates the thermal head support arm <NUM> to release the pressure contact between the thermal head <NUM> and the platen roller <NUM>, and stops the thermal head <NUM> at the second retracted position illustrated in <FIG>.

In step S607, to start M photographic printing, the main control unit <NUM> performs control to align the photographic printing start position of the M layer <NUM> of the ink ribbon <NUM> with the position opposing the thermal head <NUM>. More specifically, the main control unit <NUM> rotates the take-up bobbin <NUM> to draw the ink ribbon <NUM> from the supply bobbin <NUM> and start taking up the ink ribbon <NUM>. Once the marker detection sensor <NUM> has detected the marker <NUM> at the beginning of the M layer <NUM>, the main control unit <NUM> performs control to stop taking up the ink ribbon <NUM>.

In step S608, the main control unit <NUM> controls a return operation of the sheet <NUM>. More specifically, the main control unit <NUM> controls the conveyance roller <NUM> to convey the sheet <NUM> to the photographic printing start position illustrated in <FIG> in the direction indicated by the arrow G in <FIG>. In step S609, the main control unit <NUM> controls the thermal head <NUM> to sandwich and press the ink ribbon <NUM> and the sheet <NUM> against the platen roller <NUM>, so that the thermal head <NUM> is moved to the pressing position illustrated in <FIG>. In step S610, the main control unit <NUM> controls M photographic printing corresponding to the target image. In step S611, the main control unit <NUM> stops the thermal head <NUM> at the second retracted position illustrated in <FIG>. The processing of steps S609 to S611 is similar to that of steps S604 to S606.

Subsequently, the main control unit <NUM> performs the processing of steps S612 to S616 to perform C photographic printing corresponding to the target image. The main control unit <NUM> then performs the processing of steps S617 to S621 to perform OC photographic printing corresponding to the target image. The processing of steps S612 to S616 is similar to that of steps S607 to S611. The processing of steps S617 to S620 is similar to that of steps S607 to S610. However in step S612, to start the C photographic printing, the main control unit <NUM> performs control to align the photographic printing start position of the C layer <NUM> of the ink ribbon <NUM> with the position opposing the thermal head <NUM>. More specifically, the main control unit <NUM> stops taking up the ink ribbon <NUM> once the marker detection sensor <NUM> has detected the marker <NUM> at the beginning of the C layer <NUM>. Also in step S617, to start the OC photographic printing, the main control unit <NUM> performs control to align the photographic printing start position of the OC layer <NUM> of the ink ribbon <NUM> with the position opposing the thermal head <NUM>. More specifically, the main control unit <NUM> stops taking up the ink ribbon <NUM> once the marker detection sensor <NUM> has detected the marker <NUM> at the beginning of the OC layer <NUM>. In step S621, in the state illustrated in <FIG>, the main control unit <NUM> performs control to rotatably drive the sheet feed roller <NUM>, nip the sheet <NUM> between the sheet feed roller <NUM> and the sheet discharge roller <NUM>, and discharge the sheet <NUM> to the outside of the printer main body <NUM>. The normal photographic print processing is thus completed.

Next, an essential part of an embodiment of the present invention will be described. More specifically, an OC layer image generation method and an OC layer photographic printing method that produce the effect of emphasizing a main subject portion in the target image according to a first embodiment of the present invention will be described with reference to <FIG>. <FIG> is a flowchart illustrating processing for generating OC layer photographic print data according to the first embodiment. First, the generation of the OC layer photographic print data will be described with reference to the flowchart of <FIG>. The processing in this flowchart is implemented by the CPU <NUM> reading a program from the flash ROM <NUM> and controlling the components based on the read program.

In step S701, the main control unit <NUM> determines whether the main subject emphasis mode is selected by the user. In a case where the main subject emphasis mode is not selected (NO in step S701), the processing proceeds to step S702. In step S702, the main control unit <NUM> selects, for the OC layer <NUM>, basic photographic print data for performing low gradation photographic printing uniformly over the entire area. The image processing unit <NUM> then generates the OC layer photographic print data in which the basic photographic print data, which is low gradation pixel data (low gradation value data) for performing the low gradation photographic printing uniformly over the entire area, is arranged over the entire area.

On the other hand, in a case where the main subject emphasis mode is selected (YES in step S701), the processing proceeds to step S703. In step S703, the image processing unit <NUM> performs main subject selection processing on the target image. More specifically, at the time of transferring the OC layer <NUM>, the main control unit <NUM> acquires original image data <NUM> (see <FIG>) corresponding to the image to be printed on the sheet <NUM> using the color inks of the YMC layers <NUM>, <NUM>, and <NUM>, and selects a main subject <NUM> (see <FIG>) and extracts a contour of the main subject <NUM> from the original image data <NUM>. <FIG> schematically illustrates the image of the original image data <NUM>. The original image data <NUM> includes a person as the main subject <NUM>, and trees in the background as background subjects <NUM>. In the present embodiment, a main subject range is automatically selected based on an algorithm using face detection and contrast measurement. The selection method is not specifically limited. For example, the user may give a selection instruction via the display unit <NUM> and the operation unit <NUM>.

In step S704, the image processing unit <NUM> performs contour extraction processing on the main subject <NUM> (the main subject range) in the original image data <NUM> that is selected in step S703. The contour extraction processing on the main subject range is performed using conventional techniques such as edge detection and human detection. In step S705, the main control unit <NUM> performs display control to display a result of the contour extraction processing in step S704 on the display unit <NUM> together with the image of the original image data <NUM> in a combined manner, and asks the user whether the contour of the main subject <NUM> is appropriately extracted. As the result of the contour extraction processing, the main control unit <NUM> superimposes and displays a contour line in a specific color on the image of the original image data <NUM>. The user views the result of the contour extraction processing and performs an "OK" or "cancel" operation via the operation unit <NUM>. In step S705, in a case where a "cancel" operation is performed (NO in step S705), the processing proceeds to step S706. In step S706, the main control unit <NUM> performs main subject reselection processing. At this time, the main control unit <NUM> may select the next candidate by using the algorithm used in selecting the main subject <NUM> in step S703, or may reselect a main subject by using a different algorithm. In step S705, in a case where the user views the result of the contour extraction processing and makes an "OK" operation (YES in step S705), the main control unit <NUM> confirms the result of the contour extraction processing in step S704, and the processing proceeds to step S707. In steps S707 to S709, the image processing unit <NUM> generates the OC layer photographic print data for emphasizing the main subject <NUM>. In generating the OC layer graphical print data in steps S707 to S709, the image processing unit <NUM> generates the OC layer photographic print data by overwriting a partial region of the basic photographic print data (the low gradation pixels over the entire area) with high gradation pixels (high gradation value data) or mixed pattern data. For that purpose, in step S707, the image processing unit <NUM> prepares the basic photographic print data.

In step S708, as a first step of generating the OC layer photographic print data, the image processing unit <NUM> generates photographic print data by rendering a contour line corresponding to the contour of the main subject <NUM> extracted in step S704 into a one-pixel-wide high gradation line of high gradation pixels.

<FIG> illustrates first OC layer photographic print data <NUM> that is generated by rendering the contour line, which is the result of the contour extraction processing on the original image data <NUM>, into a one-pixel-wide high gradation line. A white portion in the first OC layer photographic print data <NUM> corresponds to low gradation pixels (low gradation value data). A black portion (a contour line <NUM>) in the first OC layer photographic print data <NUM> corresponds to high gradation pixels (high gradation value data). The first OC layer photographic print data <NUM> includes the high gradation pixels forming the contour line <NUM>, and the other low gradation pixel portion. A region <NUM> is an enlargement of a region <NUM> in the first OC layer photographic print data <NUM>. The region <NUM> includes the contour line <NUM>. The contour line <NUM> is formed of a one-pixel-wide solid line of high gradation pixels. Low gradation pixels are assigned to the other portion. The portion printed with high gradation pixels assigned thereto has low glossiness because the surface of the protective layer is roughened by application of energy higher than melting energy. The portion printed with low gradation pixels assigned thereto has high glossiness because the melting energy for normal coating is applied. Thus, in a case where the first OC layer photographic print data <NUM> is photographically printed using the OC layer <NUM>, the contour line <NUM> has low glossiness, whereas the other portion, i.e., the region of the main subject <NUM> and the background other than the contour line <NUM> has a high gloss surface. Since the OC layer <NUM> is colorless and transparent so as not to change the color tones of pictures, a visual difference between the region printed with low glossiness and the region printed with high glossiness is limited to glossiness. In other words, the contour line <NUM> is low in visibility. To enhance the main subject emphasis effect, the contour line <NUM> is to be emphasized with a certain degree of line width so that the difference in glossiness is more visible.

Thus, in step S709, the image processing unit <NUM> generates a first mixed pattern including a mixture of high gradation pixels and low gradation pixels, for an outer peripheral region as wide as three pixels from the contour line <NUM> generated in step S708 outside the main subject <NUM>.

<FIG> illustrates second OC layer photographic print data <NUM> generated in step S709. The second OC layer photographic print data <NUM> is generated based on the first OC layer photographic print data <NUM> described with reference to <FIG>. The second OC layer photographic print data <NUM> includes an enlarged contour line <NUM> into which the contour line <NUM> in the first OC layer photographic print data <NUM> is converted. A portion <NUM> is an enlargement of a portion <NUM> circled by a dotted line in <FIG>. As illustrated in the portion <NUM>, in the enlarged contour line <NUM>, a first mixed pattern <NUM> is formed around the contour line <NUM>. More specifically, the first mixed pattern <NUM> is formed in an outer peripheral region as wide as three pixels from the contour line <NUM> outside the main subject <NUM>. The first mixed pattern <NUM> includes a mixture of high gradation pixel data (high gradation value data or high gradation pixels) and low gradation pixel data (low gradation value data or low gradation pixels). The enlarged contour line <NUM> is thus a line having a width of a total of four pixels, including the one-pixel-wide contour line <NUM> and the three-pixel-wide outer peripheral region. While in the present embodiment, the outer peripheral region is the three-pixel-wide region around the contour line <NUM>, the outer peripheral region may have a width of a different number of pixels. Moreover, a size of the outer peripheral region may be changed depending on a size of the main subject <NUM>. For example, if the main subject <NUM> is small (an area of the main subject <NUM> is less than a predetermined value), a region as wide as three pixels from the contour line <NUM> may be set as the outer peripheral region. If the main subject <NUM> is large (the area of the main subject <NUM> is greater than or equal to the predetermined value), a region as wide as six pixels from the contour line <NUM> may be set as the outer peripheral region.

The first mixed pattern <NUM> is generated using an algorithm in which more than two high gradation pixels are not continuous, i.e., three or more high gradation pixels are not continuous. The printer <NUM> according to the present embodiment includes the thermal head <NUM> having a resolution of <NUM> dots per inch (dpi) that is commonly used in a thermal transfer printer for picture printing. Two pixels correspond to a photographic printing distance of <NUM>. If high gradation pixels are continuous for a distance of <NUM> or more in the main scan direction or sub scan direction of the printer <NUM>, a defect such a separation failure or abnormal noise can occur. Thickening the contour line <NUM> with the first mixed pattern <NUM> generated using the foregoing algorithm prevents the occurrence of a defect such as a separation failure and abnormal noise.

The first mixed pattern <NUM> including a mixture of high gradation pixels and low gradation pixels has a low apparent reflectance (glossiness) because the printed surfaces of the dispersed high gradation pixel portions are roughened, compared to the portion printed with low gradation pixels. Accordingly, the contour line <NUM> and the first mixed pattern <NUM> can be visually observed as an integrated line. After completion of the processing for generating the enlarged contour line <NUM> in step S709, then in step S710, the image processing unit <NUM> ends the generation of the OC layer photographic print data. The generated second OC layer photographic print data <NUM> is used in the OC photographic print processing of step S620 in the flowchart illustrating the normal photographic print processing described with reference to <FIG>, so that the photographic printing using the OC layer <NUM> is performed.

<FIG> schematically illustrates a photographic printout <NUM> printed based on the original image data <NUM> and the second OC layer photographic print data <NUM>. The photographic printout <NUM> includes a main subject portion <NUM> that has a glossy surface coated by normal OC processing (OC layer transfer with low gradation value data). On the other hand, a contour line of the main subject portion <NUM> has low glossiness because of OC layer transfer with high gradation value data. For an outer peripheral region around the contour line, the OC layer <NUM> is transferred by using the first mixed pattern <NUM> including a mixture of low gradation values and high gradation values, so that the outer peripheral region forms a low gloss portion <NUM> that has higher glossiness than the contour line and lower glossiness than the main subject portion <NUM> coated by the normal OC processing. For a background region <NUM> outside the outer peripheral region (which is a region other than the subject region, the contour line, and the outer peripheral region), the OC layer <NUM> is transferred by the normal OC processing. As described above, the photographic printout <NUM> emphasizing the main subject portion <NUM> is achieved by expressing a difference in glossiness in the contour portion of the main subject portion <NUM>.

In other words, the boundary of the main subject region can be clearly emphasized by transferring the OC layer so that the main subject region has high glossiness and the contour line of the main subject has high gradation and low glossiness. Moreover, the first mixed pattern <NUM> is used to transfer the OC layer <NUM> to the outer peripheral region of the main subject. This provides a less glossy, matte surface finish, making it possible to output a printout with an emphasized bokeh effect.

Next, a second embodiment of the present invention will be described with reference to <FIG>. The second embodiment is different from the first embodiment in generation of OC layer photographic print data. Since the configuration of the printer <NUM> and the normal photographic print processing are the same as those in the first embodiment, a description thereof will be omitted.

<FIG> is a flowchart illustrating processing for generating OC layer photographic print data according to the second embodiment. First, the generation of the OC layer photographic print data will be described with reference to the flowchart of <FIG>. Similarly to the processing in the flowchart of <FIG>, the processing in this flowchart is implemented by the CPU <NUM> reading a program from the flash ROM <NUM> and controlling the components based on the read program.

The processing of steps S901 to S909 is similar to that of steps S701 to S709 in the flowchart for generating the OC layer photographic pint data in <FIG> according to the first embodiment. A description thereof will thus be omitted.

In the present embodiment, in step S910, the image processing unit <NUM> converts a background region, which is outside the first mixed pattern <NUM> in the outer peripheral region of the contour line <NUM> in the second OC layer photographic print image data <NUM> generated in step S909, into a second mixed pattern including a mixture of high gradation pixels and low gradation pixels. In the present embodiment, the background region refers to the region other than the main subject region and the enlarged contour line <NUM> (including the contour line <NUM> and the outer peripheral region of the contour line <NUM>).

<FIG> illustrates third OC layer photographic print data <NUM> generated in step S909. The third OC layer photographic print data <NUM> is generated based on the second OC layer photographic print data <NUM> described with reference to <FIG>. An enlarged portion <NUM> is an enlargement of a partial region <NUM> of a main subject region in the third OC layer photographic print data <NUM> in <FIG>. An inside region <NUM> of the enlarged portion <NUM> includes low gradation pixels and does not include high gradation pixels. A portion <NUM> is an enlargement of a partial region <NUM> that circles a part of the enlarged contour line <NUM> (including the contour line <NUM> and the outer peripheral region) with a dotted line in <FIG>. As illustrated in the portion <NUM>, the enlarged contour line <NUM> includes the contour line <NUM> and the outer peripheral region around the contour line <NUM> that are formed adjacent each other. The contour line <NUM> is a one-pixel-wide line of high gradation pixels. The outer peripheral region is formed of the first mixed pattern <NUM> including a mixture of high gradation pixel data and low gradation pixel data. The third OC layer photographic print data <NUM> further includes a second mixed pattern <NUM> that forms the background region outside the outer peripheral region. The second mixed pattern <NUM> is a pattern including a mixture of high gradation pixel data and low gradation pixel data, but the proportion of high gradation pixels in the second mixed pattern <NUM> is lower than that in the first mixed pattern <NUM>. A region <NUM> is an enlargement of a part <NUM> of the background region in the third OC layer photographic print data <NUM> illustrated in <FIG>. An inside of the region <NUM> is formed of the second mixed pattern <NUM>. The density of high gradation pixels (the proportion of high gradation pixels) in the second mixed pattern <NUM> is set to be lower than that in the first mixed pattern <NUM>. After the setting of the second mixed pattern <NUM>, in step S911, the generation of the OC layer photographic print data according to the present embodiment ends. The third OC layer photographic print data <NUM> generated in this manner is used in the OC photographic print processing in step S620 of the flowchart illustrating the normal photographic print processing described with reference to <FIG>, so that the photographic printing using the OC layer <NUM> is performed.

<FIG> schematically illustrates a photographic printout <NUM> printed based on the original image data <NUM> and the third OC layer photographic print data <NUM>. The photographic printout <NUM> includes a main subject portion <NUM> that has a high gloss surface coated by the normal OC processing (the OC layer transfer with low gradation value data). On the other hand, a contour line of the main subject portion <NUM> has low glossiness because of the OC layer transfer with high gradation value data. For an outer peripheral region around the contour line, the OS layer <NUM> is transferred by using the first mixed pattern <NUM> including a mixture of low gradation values and high gradation values, so that the outer peripheral region forms a low gloss portion <NUM> that has higher glossiness than the contour line and lower glossiness than the main subject portion <NUM> coated by the normal OC processing. A background region outside the outer peripheral region forms a semi-glossy portion <NUM> that has slightly higher glossiness than the low gloss portion <NUM> because the OC layer <NUM> is transferred using the second mixed pattern <NUM> where the proportion of high gradation pixels is lower than that in the first mixed pattern <NUM>. As described above, an effect of further emphasizing the main subject can be achieved by making the surface reflectance of the main subject and that of the background region different while emphasizing the contour portion.

In the foregoing embodiments, the image processing unit <NUM> may be configured to perform face detection processing, and may generate OC layer photographic print data by selecting a person with a face detected by the face detection processing as a main subject and detecting a contour of the person with the detected face.

Each of the first mixed pattern <NUM> and the second mixed pattern <NUM> may have a change within the pattern. For example, the density (the proportion) of high gradation pixels may be reduced with increasing distance from the contour line. The gradation values of high gradation pixels may be made variable to change the magnitude of the emphasizing effect.

In the second embodiment, the entire background is formed of the second mixed pattern <NUM> as the background region. Alternatively, a region within a predetermined range from the contour line of the main subject (a region greater than the outer peripheral region) may be formed of the second mixed pattern <NUM> as the background region, and a background portion farther from the main subject may be formed of low gradation pixels.

While the main subject in a picture has been described as the target to be emphasized, the foregoing embodiments are also applicable to a specific image range, in artificially generated image data, where contour extraction can be performed. While in the foregoing embodiments, a printer that is a printing apparatus has been described as an example, the foregoing embodiments may be implemented in a printing system where a printer and a print control apparatus such as a personal computer (PC) are connected to each other. In this case, the normal photographic print processing illustrated in <FIG> is performed by the printing apparatus, the processing for generating the OC layer photographic print data illustrated in <FIG> or <FIG> is performed by the print control apparatus, and the generated OC layer photographic print data is transmitted to the printing apparatus.

The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.

Claim 1:
A print control apparatus for transferring transparent protective overcoat ink using a thermal transfer printing apparatus onto an image printed on a substrate, the print control apparatus comprising:
extraction means (<NUM>, <NUM>) configured to extract a contour of a subject (<NUM>) in the image (<NUM>); and
control means (<NUM>, <NUM>) configured to generate print data (<NUM>, <NUM>) for transferring the protective overcoat ink using the thermal transfer printing apparatus, based on the extracted contour of the subject (<NUM>),
wherein the control means (<NUM>, <NUM>) is configured to generate the print data (<NUM>, <NUM>) by assigning a high gradation value to achieve low glossiness to a contour line (<NUM>) corresponding to the extracted contour of the subject (<NUM>) and assigning a low gradation value to achieve high glossiness to a region inside the contour line corresponding to the subject (<NUM>), characterised in that the control means is further configured to generate the print data by assigning a mixture (<NUM>) of the high gradation value and the low gradation value to an outer peripheral region of the subject (<NUM>) which is outside the contour line so that the outer peripheral region has higher glossiness than the contour line (<NUM>) and lower glossiness than the region inside the contour line corresponding to the subject (<NUM>).