JPH0965108A - Device and method for converting page description - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the decline of image quality at the time of converting an image object expressed by image description to page description and to reduce the size of the page description compared to the case of individually page describing the plural image objects. SOLUTION: When the image description including the set of objects including the image object and an image processing instruction to the image object is inputted from an input means 11, a separation means 16 separates the image object from the image description, an execution means 18 executes a processing based on an image instruction to the image object and a page description generation means 20 generates the page description based on the image object to which the image processing is executed. Also, when the set of the objects includes the plural image objects, after a synthesis means 19 synthesizes the image objects, the page description is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conversion apparatus and method for converting document data in which image objects are mixed together with graphics objects, text objects, etc. into a page description, and more particularly to application of image processing such as color conversion. The present invention relates to a technique for converting data related to a image object represented by an image description into a representation in a page description language.

[0002]

2. Description of the Related Art For example, in desktop publishing (DTP), in order to create an electronic document, an electronic block making process and an output process are required. Descriptions are made in (PDL), and the output of the block copy is mainly printed directly by a page description printer. However, when trying to apply image processing such as color conversion, spatial coordinate transformation, filtering, etc. to an image object, it is difficult for the page description language to express the image processing sufficiently, and more than one image object is superimposed. Image processing such as watermark composition cannot be described.

Therefore, conventionally, in order to print an electronic block in which image objects to which the above-mentioned image processing is applied together with text objects and graphics objects are printed by a page description printer, images, graphics, texts, etc. An image description that can express multiple objects in a mixed manner and can sufficiently express the application of image processing to an image object (Li
(ve Picture, PhotoShop, etc.) was used to create the description of the block copy data. That is, an electronic block description including image processing of an image object is created using an image description, and this description is decomposed (description analysis and rasterization processing) with a dedicated composer to create a raster image, The raster image is printed by the page description printer.

[0004]

The print resolution of the page description printer, the color correction processing according to the characteristics of the color material, the halftone dot processing of the image, etc. are different from printer to printer. Therefore, depending on the printer used for the output processing. However, there is a problem in that appropriate image processing is not performed, moire and color shift occur in the printed image object portion, and jaggies occur in the contour line.

However, in the prior art, when the image description is decomposed and rasterized, the text object and the graphics object included in the image description together with the image object are also converted into the raster image, regardless of the type of the object. Instead, the entire object is converted into a single raster image, so that appropriate image processing corresponding to the printer cannot be performed on the image object, and the printed image quality deteriorates.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a page description conversion apparatus and method which prevent deterioration of image quality when converting an image object represented by an image description into a page description. With the goal. Further, according to the present invention, the size of the page description is reduced as compared with the case of individually describing each of these image objects by performing a combining process on a plurality of image objects included in the image description and then converting the image object into a page description. An object of the present invention is to provide a page description conversion device that can be reduced in size.

In Japanese Patent Laid-Open No. 5-210720, a command separated from the PDL in order to synthesize another image object input by a scanner or the like with image data in which an image object is mixed with a text object and a graphics object. Discloses an invention for processing a part of image data and another image object. However, according to the present invention, since the processing into the image object is limited to the command expressed by the PDL, it is not possible to carry out a sufficient image processing such as watermark composition, and the present invention described below The purpose, structure and effect are completely different.

[0008]

In order to achieve the above object, according to the present invention, after image processing such as color conversion is performed on an image object included in a set of objects in the image description, the image description is performed. To a page description. That is, in distinction from a text object or a graphics object, after appropriate image processing is performed on the image object, it is converted into a raster image together with the text object or graphics object, and after performing predetermined image processing on the object. Print processing is performed by the page description printer.

Further, in the page description conversion device of the present invention,
When an image description including a set of objects including an image object and an image processing instruction for the image object is input from the input unit, the separating unit separates the image object from the image description, and the executing unit separates the image object. Then, the process based on the image command is executed. Therefore, at this point, image processing such as color conversion is performed on the image object included in the image description.

Then, the page description generating means generates a page description based on the image object on which the image processing has been executed. Therefore, when the image description includes an image object together with a text object and a graphics object, and an image processing instruction for the image object is described, a predetermined image processing is appropriately performed on the image object before the page description. Because it is converted, a high quality document image can be printed on the page description printer.

Further, in the page description conversion device of the present invention,
When the image description includes a plurality of image objects, the area calculation means calculates the area surrounding all of these image objects, and the image processing is executed by the execution means. Are combined in the calculated area. Then, the page description generation means generates a page description based on the image object combined in this area. That is, by combining a plurality of image objects included in the image description in the area and then converting them into a page description,
The size of the page description describing a plurality of image objects is made smaller than the case where these image objects are individually described in pages.

[0012]

1 shows the configuration of a page description conversion apparatus according to an embodiment of the present invention. The page description conversion device includes input means 11 for inputting an image description, description analysis means 12 for analyzing the input image description, and description conversion means 13 for generating a page description based on the analysis result. The page description conversion device is a device for converting an image description into a page description as described later, and outputs the converted page description to a page description printer to output a document image.

An image description is input to the input means 11 from an external workstation or the like, and the input means 11 processes the input image description and outputs it to the description analysis means 12. This image description includes a set of objects that make up the document, layout information (position coordinates, size, etc.) of these objects within the document, and image processing commands (operators) for these objects such as color conversion and watermark composition. And are included. It should be noted that the set of objects is composed of the identifiers of the respective object data stored in the external storage device or the like, and in the present embodiment, the types of objects include text, graphics, and images forming a document. That is,
The image description includes a set of objects including image objects and image processing instructions for the image objects.

The description analysis means 12 performs grammatical analysis and semantic analysis on the image description input by the input means 11 to generate a syntax tree of an internal data structure. The description conversion unit 13 includes a layout conversion unit 14 that separates each object in the image description into different threads for each type, and an object conversion unit 15 that converts these objects into a page description for each type.

The layout conversion means 14 separates the image object in the image description into a thread different from other types of objects such as text and graphics, and a plurality of image objects included in the image description. A region calculating means 17 for calculating a circumscribing circumscribed rectangular region is provided. The object conversion unit 15 includes an execution unit 18 that executes a predetermined image process on the image object separated into threads.
In parallel with the execution of image processing, there are provided a synthesizing means 19 for synthesizing each image object in the circumscribed rectangular area and a page description generating means 20 for converting each type of object into a page description.

In the page description conversion apparatus having the above configuration, when the image description is input from the input means 11, the description analysis means 12 generates an internal data structure of the syntax tree based on the image description.
Layout conversion means 1 from the execution sequence of this internal data structure
4 generates a thread for each object type, and the object conversion means 15 performs a predetermined image processing on each thread to convert it into a page description. In this embodiment, text and graphics are processed as objects of the same type, and images are processed as objects of different types.

The processing performed by the layout conversion means 14 described above is performed in the procedure shown in FIG. First, the description analysis means 1
When the internal data structure of the syntax tree is input from 2, the layout conversion means 14 fetches the first execution string indicated by the current pointer from the internal data structure of the syntax tree and updates the current pointer to the next execution string (step S1). Next, the separation unit 16 determines the object type of the fetched execution sequence (step S2), and performs processing for separating the object thread into image or text and graphics.

As a result of the above judgment, when the object type is image, the separating means 16 newly creates a thread for the image object (step S3),
The calculation processing of the circumscribed rectangular area is performed by the area calculation means 17 (steps S4 to S6). In the calculation process of the circumscribed rectangular area, first, as the coordinate values of the circumscribed rectangular area surrounding the image object included in the document, the minimum values Xmin and Ymin and the maximum values Xmax and Ymax of the X coordinate and the Y coordinate are set.
Is held as an initial value (step S4). Specifically, as shown in FIG. 3, the coordinate value I of the upper left corner (TopLeft) in the X direction of the first input image object is I.
Xmin is held as the minimum value Xmin in the X direction, and the coordinate value IXmax of the lower right corner (Bottom Right) in the X direction is set to X.
The maximum value Xmax in the direction is held, and the upper left corner in the Y direction (T
opLeft) coordinate value IYmin is the minimum value Ymin in the Y direction.
As the bottom right corner in the Y direction (BottomRight
The coordinate value IYmax of t) is held as the maximum value Ymax in the Y direction, and the circumscribed rectangular area D surrounding this image object is calculated.

Then, the circumscribed rectangular area in the X direction (image existing area) held as described above is updated by comparison with the next image object (step S5). Specifically, the X of TopLeft of the next image object
If the coordinate value IXmin is smaller than the minimum value Xmin in the X direction, IXmin is substituted for the minimum value Xmin, and the X coordinate value IXmax of the BottomRight of the next image object.
Is larger than the maximum value Xmax in the X direction, IXmax is substituted for the maximum value Xmax. Next, in the same manner as above, the circumscribed rectangular area is updated in the Y direction (step S6). Specifically, the T of the next image object
The Y coordinate value IYmin of opLeft is the minimum value Ymin in the Y direction.
If smaller, IYmin is substituted for the minimum value Ymin,
The Y coordinate value IYmax of BottomRight of the next image object is compared with the maximum value Ymax in the Y direction, and if larger than this, IYmax is substituted for the maximum value Ymax.

Next, the operator and the parameter of the fetched execution sequence are added to the operator execution sequence of the newly created image thread to update the thread (step S
7) Then, the next execution string indicated by the current pointer is fetched from the internal data structure of the input syntax tree, and the current pointer is updated to the next execution string (step S8). Next, the separating unit 16 determines the object type of the newly fetched execution column (step S9), and when the object type of the next execution column is an image, the above-described processing from step S5 is repeated.

By repeating the process for such an image object, the minimum circumscribed rectangle surrounding all the image objects included in the image description is calculated as shown in FIG. 4, and the thread execution sequence is described later. An internal data structure (FIG. 5) in which an operator execution sequence is associated with each thread therein is configured. In the example shown in FIG. 4, there are four image objects I1, I2, I3, and I4 on the XY plane, and the rectangle shown by the broken line in the figure is the smallest surrounding I1, I2, I3, and I4. It is a circumscribed rectangle. The size of the minimum circumscribed rectangular area in the X direction is | Xmax-X
min |, the size in the Y direction is | Ymax-Ymin |, and the combined position is (Xmin, Ymin).

As a result of the above determination (step S9), if the object type of the next execution column is other than image,
The size and composition position of the minimum circumscribed rectangular area are inserted at the head of the image thread newly created in step S3 (step S10), and the type (step S2) of the separating means 16 is judged again, and graphics (or text) is entered. Processing for the object or NULL.

That is, when the object type is graphics or text as a result of the judgment in step S2, the judgment separating means 16 newly creates a thread for the graphics (text) object (step S11), and this graphic is displayed. The operator and the parameter of the fetched execution sequence are added to the operator execution sequence of the thread and the thread is updated (step S1.
2) The next execution string indicated by the current pointer is fetched from the internal data structure of the input syntax tree and the current pointer is updated to the next execution string (step S13). Next, the separating means 16 determines the object type of the newly fetched execution sequence (step S14), and when the object type of the next execution sequence is graphics (or text), the above-mentioned processing from step S12 is repeated. To do.

On the other hand, the result of the above judgment (step S14)
As a result, when the object type of the next execution column is other than graphics or text, the separation means 16 determines the type again (step S2), and the process for the image object or NULL is performed again. That is, as a result of the determination in step S2, when the object type is NULL, the end identifier is assigned to the pointer to the next thread, the processing by the layout conversion means 13 is ended, and the processing by the object conversion means 15 described later is performed. .

As a result of the series of processes described above, as shown in FIG. 5, the internal data structure is an internal data structure composed of two types of execution sequences, that is, a thread execution sequence and an operator execution sequence. Each column has a list format data structure. Each entry in the thread execution sequence list corresponds to one thread, and the type identifier of the object included in the thread,
It contains a pointer to the next thread and a pointer to the operator execute sequence corresponding to that thread. The type identifier of the object indicates the type of the object included in the thread, and since the text is classified into graphics in this embodiment, there are two types of objects: image and graphics. The pointer to the next thread points to the next thread to convert,
The pointer at the end of the thread execution sequence points to the end identifier indicating the end of the thread execution sequence. The pointer to the operator execution sequence indicates the description of the process for the object, and the operator execution sequence corresponding to each thread is configured.

Each entry of the operator execution sequence list corresponds to one operator and includes an operator, a pointer to the next operator, and operator parameters. The operator is an image processing command for an object, and for example, enlargement or reduction, color conversion, spatial coordinate transformation, filtering, watermark composition, etc. are set as the image processing command. The pointer to the next operator indicates the operator to be converted next, and the pointer at the end of the operator execution sequence points to the end identifier indicating the end of the operator execution sequence. In the example shown in FIG. 5, the operator parameter has one entry for each operator, but in reality, each operator may have a plurality of entries.

The processing performed by the object converting means 15 is performed according to the procedure shown in FIG. First, layout conversion means 1
When the thread execution sequence (FIG. 5) generated in 4 is input, the first entry of the thread execution sequence is fetched and the current pointer is updated to the next entry (step S
21). Next, it is determined whether the fetched entry is the end identifier (step S22), and if it is the end identifier, the conversion process is ended. On the other hand, if it is not the end identifier, the thread type (that is, the object type) of the fetched entry is judged (step S23), and if the type is an image, the execution means 18 causes the operator execution sequence corresponding to the thread. Is acquired and the operator is fetched from the list (step S24). At the same time, the current pointer of the operator is updated to the next entry.

Next, it is judged whether the operator fetched by the execution means 18 is the end identifier (step S2).
5) If it is not the end identifier, the fetched operator is executed to execute a predetermined image process on the fetched entry (image object) of the thread execution sequence (step S26). Processing for such an image object (steps S24 to S2
6) is sequentially executed for each entry of the operator execution column,
When the current pointer becomes the end identifier (step S25), the page description generation means 20 converts the image object into a page description (step S2).
7).

The above process fetches the thread list of the image object (steps S21 and S2).
3) Each time it is repeated, each image object is combined in the circumscribed rectangular area by the combining means 19 in the operator execution process (step S26). Therefore, each image object is converted into a page description while being combined in the circumscribed rectangular area.

On the other hand, when it is determined that the thread type is graphics (or text) (step S2
3) The operator execution sequence is acquired from the thread entry, the operator is fetched from the list, and the current pointer is updated to the next entry (step S2).
9). Then, the operator judges whether or not it is the end identifier (step S30), and when it is not the end identifier,
The fetched operator is converted into a page description operator (step S31), and the processing from step S29 is repeated. On the other hand, the result of the above determination (step S3
0), if the operator is the end identifier, the processing in and after step S21 is repeated, and the entry of the fetched thread execution sequence is the end identifier (step S2).
When 2) is reached, the process ends.

[0031]

[Embodiment] An example of processing for expressing a document by an image description and converting it into a page description will be described. Figure 7
The document image shown in is printed by the page description printer based on the page description, and is composed of five objects as shown in FIG. Object 1 is text, Objects 2-4 are images,
The object 5 is graphics, and the image object 4 is watermark-synthesized with the image object 3.

FIG. 9 shows an example in which the document image of FIG. 7 is represented by an image description. Object 1 is read (process 1), and the read object 1 is 2.
It is enlarged to 0 times (process 2), the object 2 is read (process 3), the object 2 is overlaid on the object 1 and combined (process 4), the object 3 is read (process 5), and the combined object 1, The object 3 is superimposed on the object 2 (process 6), the object 4 is read (process 7), and the combined object 1,
The object 4 is overlaid on two and three (process 8), the object 5 is read (process 9), the read object 5 is enlarged 1.8 times (process 10), and the combined objects 1, 2 are obtained. The object 5 is overlaid on 3, 4, and synthesized (process 11). As a result of such a series of processing, the document image shown in FIG. 7 can be generated.

FIG. 10 is a graphical representation of the same description as in FIG. 9, and in processing 1, 2, 4, 6, 8, and 11, objects 1 to 5 are sequentially combined. Here, when the page description conversion apparatus according to the present invention is used,
The structure of the image description shown in FIGS. 10 and 10 is converted into the structure shown in FIG. That is, when the image description is converted, the thread is divided into three threads A, B, and C as shown in FIG. Therefore, in the image thread B, the three image objects 2 to 4 are superimposed and combined on the minimum circumscribed rectangular area, converted into one image object, and then combined with other types of objects of the graphics thread A or C.

In this way, the image thread B is separated from the other types of threads B and C, and each thread is converted into a page description separately, whereby image processing such as color conversion and filtering is performed on the image object. It can be applied, or an image description expressing image processing such as watermark composition can be converted into a page description and expressed. Therefore, it is possible to perform appropriate image processing for the printer on the image object and print a high-quality image. Also, by overlapping and composing a plurality of image objects on the minimum circumscribed rectangular area to form one image object, the size of the page description can be made smaller than in the case of individually describing these image objects. It will be possible.

The image description format is not limited to the above-described format, and may be a page description language including extended instructions such as an image operator.

[0036]

As described above, according to the page description conversion apparatus and method of the present invention, since the image object is processed separately from the graphics object and the text object, image processing such as color conversion and filtering can be performed. It is possible to convert an image description including an image object accompanied by a watermark synthesizing process into a page description that can be directly printed by a page description printer without degrading image quality. Further, according to the page description conversion apparatus of the present invention, when the image description includes a plurality of image objects, the image objects are combined and the combined image object is converted into the page description. The size of the page description can be reduced as compared to the case where the objects are individually expressed by the page description.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a page description conversion apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure by a layout conversion unit according to an exemplary embodiment of the present invention.

FIG. 3 is a conceptual diagram illustrating a circumscribed rectangular area.

FIG. 4 is a conceptual diagram illustrating a circumscribed rectangular area that surrounds a plurality of image objects.

FIG. 5 is a conceptual diagram illustrating an internal data structure of a thread execution sequence.

FIG. 6 is a flowchart showing a processing procedure by an object conversion unit according to an embodiment of the present invention.

FIG. 7 is a diagram showing an example of a document image printed based on a page description.

FIG. 8 is a diagram showing an example of objects forming a document image.

FIG. 9 is an explanatory diagram showing an example of the configuration of an image description expressing a document image.

FIG. 10 is a graph showing an example of the structure of an image description expressing a document image.

FIG. 11 is a graph showing an example of a configuration after conversion of an image description expressing a document image.

[Explanation of symbols]

11 ... Input means, 12 ... Descriptive analysis means, 1
3 ... conversion means, 14 ... layout conversion means,
15 ... Object conversion means, 16 ... Separation means, 17 ... Area calculation means, 18 ... Execution means, 19 ... Compositing means, 20 ... Page description generation means,

Claims (3)

[Claims] 1. An input unit for inputting an image description including a set of objects including an image object and an image processing instruction for the image object; a separating unit for separating an image object from the image description; and a separated image object. And an execution unit that executes a process based on the image processing instruction, and a page description generation unit that generates a page description based on the image object on which the processing based on the image processing instruction is executed. Page description converter. 2. The page description conversion apparatus according to claim 1, wherein the set of objects includes a plurality of image objects, and an area for calculating an area surrounding all the image objects separated by the separating means. The page description generating means further includes a calculating means and a synthesizing means for synthesizing each of the image objects processed by the executing means in the area, and the page description generating means includes a page based on the image object synthesized in the area. A page description conversion device characterized by generating a description. 3. A process of inputting an image description including a set of objects including image objects and an image processing instruction for the image object, and processing the image objects included in the set of objects based on the image processing instruction. A page description conversion method, characterized in that the image description is converted into a page description after executing.