This application claims priority from Japanese Patent Applications Reference No.11-232692, filed Aug. 19, 1999 and No.11-232693, filed Aug. 19, 1999, the entire content of which is incorporated herein by reference for all purposes.
The present invention relates to a printer host for expanding a bundle of drawing commands of one page stored as a spool file, into image data for each of the bands, and a storage medium storing an operation program therefor.
In general, as shown in FIGS. 1, 2 and 11, a bundle of drawing commands of one page is stored as a spool file 39 in a hard disk unit 26 of a printer host. At the time of printing, the spool file 39 stored in the hard disk unit 26 is directly and temporarily stored in a RAM 22 of the printer host. In order to expand the drawing command, as image data, in a band memory 55, the printer host prepares a band-corresponded drawing command full list 53c to show the correspondence of each of the drawing commands to the band or bands. The full list 53c shows memory addresses of the drawing commands corresponding to the respective bands. Next, reference is made to the memory addresses in the full list 35c, drawing commands corresponding to the respective bands are called from the spool file stored in a spool file memory 54c in RAM 22 and are expanded as image data on the band memory 55. The image data expanded on the band memory 55 are subjected to the RGB-CMYK color-changing processing and to the half-tone processing, converted into a command that can be interpreted by the printer, and are then sent to the printer.
Concretely described here is a case where an image shown in FIG. 9 is to be printed.
It is presumed here that the image is drawn on the regions of coordinates (0, 0) to (577, 992) and is processed being divided into five bands, i.e., 0-th band to fourth band. On the regions of coordinates (0, 0) to (577, 992) are drawn a triangle represented by a drawing command A, a square represented by a drawing command B, a circle represented by a drawing command C and an image represented by a drawing command D.
As shown in FIG. 10, in the spool file are stored data related to the drawing commands A, B, C and D of one page. For example, the drawing command A includes an operation code stating xe2x80x9cdraw a trianglexe2x80x9d, and three vertex coordinates of the triangle. The drawing command D includes an operation code for starting the imaging, diagonal point coordinates of a rectangular region of image, and image data.
When forming a band-corresponded drawing command list, it is learned to which band the image belongs from the coordinate data of image possessed by the respective drawing commands. As for the drawing command A representing a triangle, for example, it is learned that it belongs to the 0-th band and to the first band from the data of vertex coordinates of the triangle. Referring to FIG. 11, a band-corresponded drawing command full list 53c is formed in which the drawing command A is related to the 0-th band, the drawing command A and the drawing command C are related to the first band, the drawing command B and the drawing command C are related to the second band, the drawing command B is related to the third band, and the drawing command B and the drawing command D are related to the fourth band. As described above, however, the band-corresponded drawing command full list 53c is not the one in which the bands and the drawing commands are directly related to each other, but is the one in which the bands are related to the addresses in the RAM 22 storing the respective drawing commands.
According to the prior art, however, the spool file stored in the hard disk unit is directly stored in a memory; i.e., the memory must have a large storage capacity. In particular, very large storage capacity is necessary when a large number of drawing commands are included in the data of one page or when the drawing command includes image data.
According to the prior art, further, the drawing commands to be expanded in the bands are all related to all of the band columns in the band-corresponded drawing command list. Therefore, in the full list 53c shown in, for example, FIG. 11, the drawing command B is related to three bands, i.e., related to the second band, to the third band and to the fourth band. Thus, a large number of drawing commands (in practice, addresses of drawing commands) are picked up on the list, and the memory must have a large storage capacity. In particular, when the band width is narrow and there exist a large number of bands of one page in total, then, a single drawing command is related to many bands, and the number of the drawing commands picked up on the list becomes very large.
The present invention was accomplished in view of the above problems inherent in the prior art. And the object of the present invention is to provide a printer host capable of decreasing the quantity of data stored in the memory and a storage medium storing an operation program for the printer host.
To accomplish the object, the first printer host which comprises an auxiliary storage unit and a main storage unit, and expands a bundle of drawing commands of one page stored, as a spool file, in the auxiliary storage unit, into image data for each of bands of a predetermined band width, further comprises;
list-forming means for forming a band-corresponded drawing command list showing the correspondence of each of the drawing commands to the band or bands, by making reference to the spool file stored in the auxiliary storage unit;
a drawing command storage region which is a portion of the main storage unit and stores the drawing command of one band;
an image data expanding region which is another portion of the main storage unit and in which the image data of one band is expanded;
drawing command storage control means which successively reads out the drawing commands corresponding to the respective bands from the spool file stored in the auxiliary storage unit according to the band-corresponded drawing command list, and stores the drawing command of one band that is read out in the drawing command storage region; and
image data expanding means which converts the drawing command of one band stored in the drawing command storage region into image data and expands the image data in the image data expanding region.
To accomplish the object, the second printer host according to the first printer host, comprises:
access judging means which judges whether a drawing command among the plural drawing commands is the one that is once stored in the drawing command storage region or is the one that has not yet been stored in the drawing command storage region but has been stored in the auxiliary storage unit; wherein
when it is judged by the access judging means that the drawing command is the one that has not yet been stored in the drawing command storage region but has been stored in the auxiliary storage unit, the drawing command storage control means makes reference to the band-corresponded drawing command list and accesses to the auxiliary storage unit.
To accomplish the object, provided is the third printer host according to any one of the first printer host or the second printer host, wherein the list-forming means forms a drawing command difference list as the band-corresponded drawing command list, in which the start of drawing command representing the image is related to a band corresponding to the start position of the image at a moment when the plural drawing commands are expanded into images, and the end of the drawing command representing the image is related to a band corresponding to the end position of the image when each of the plural drawing commands is expanded into images.
To accomplish the object, provided is the fourth printer host according to the third printer host, wherein the list-forming means forms a one-band drawing command list as a portion of the band-corresponded drawing command list by referring to the drawing command difference list, in which the drawing commands corresponding to one band are all related to the one band in which the image expansion is to be carried out from now, and the drawing command storage control means makes reference to the one-band drawing command list and stores the drawing command of one band in the drawing command storage region.
To accomplish the object, the first storage medium for a printer host having an auxiliary storage unit and a main storage unit, stores a program which expands a bundle of drawing commands of one page stored, as a spool file, in the auxiliary storage unit, into image data for each of the bands of a predetermined band width, the storage medium storing the program which comprises the steps of:
forming a band-corresponded drawing command list showing the correspondence of each of the drawing commands to the band or bands by making reference to the spool file stored in the auxiliary storage unit;
successively reading out drawing commands corresponding to the respective bands from the spool file stored in the auxiliary storage unit according to the band-corresponded drawing command list, and storing the drawing command of one band that is read out in the drawing command storage region which is a portion of the main storage unit for storing the drawing command of one band; and
converting the drawing command of one band stored in the drawing command storage region into image data and expanding the image data in the image data expanding region which is another portion of the main storage unit for expanding the image data of one band.
To accomplish the object, the second storage medium according to the first storage medium, stores a program comprising a step of:
judging whether a drawing command among the plural drawing commands is the one that is once stored in the drawing command storage region or is the one that has not yet been stored in the drawing command storage region but has been stored in the auxiliary storage unit; wherein
when it is judged by the access judging step that the drawing command is the one that has not yet been stored in the drawing command storage region but has been stored in the auxiliary storage unit, the drawing command storage control step accesses the auxiliary storage unit.
To accomplish the object, the third storage medium according to any one of the first storage medium or the second storage medium, stores a program comprising a step of forming a drawing command difference list as the band-corresponded drawing command list, wherein the start of drawing command representing the image is related to a band corresponding to the start position of the image at a moment when the plural drawing commands are expanded into images, and the end of the drawing command representing the image is related to a band corresponding to the end position of the image when each of the plural drawing commands are expanded into images.
According to the invention as described above, the band-corresponded drawing command list is formed by making reference to the spool file stored in the auxiliary storage unit and, then, the drawing command related only to the desired band is called from the auxiliary storage unit by making reference to the list and is stored in the memory which is the main storage unit. Therefore, the memory region of only one band is enough for storing the drawing command, and the data quantity that needs be stored in the memory can be greatly reduced.
To accomplish the object, the fifth printer host expanding a bundle of drawing commands of one page stored as a spool file into image data for each of the bands of a predetermined band width, the printer host comprises:
list-forming means for forming a drawing command difference list in which the start of drawing command representing the image is related to a band corresponding to the start position of the image and the end of the drawing command representing the image is related to a band corresponding to the end position of the image when each of the plural drawing commands is expanded into images by making reference to the spool file;
an image data expanding region where the image data of one band are expanded; and
drawing command processing means for successively reading out the drawing commands corresponding to the respective bands from the spool file based upon the drawing command difference list, converts the drawing command of one band that is read out into image data, and expands the image data in the image data expanding region.
To accomplish the object, provided is the sixth printer host according to the fifth printer host, wherein:
the list-forming means forms a one-band drawing command list by making reference to the drawing command difference list, in which the drawing commands corresponding to one band are all related to the band in which the image expansion is to be carried out; and
the drawing command processing means makes reference to the one-band drawing command list to convert the drawing command of one band into image data, and expands the image data in the image data expanding region.
To accomplish the object, the seventh printer host according to the fifth or the sixth printer host, comprises:
an auxiliary storage unit storing the spool file; and
a main storage unit in which are formed a drawing command storage region storing therein the drawing command of one band, and the image data expanding region; wherein
the drawing command processing means comprising:
drawing command storage control means successively reading out the drawing commands corresponding to the respective bands from the spool file stored in the auxiliary storage unit based on the drawing command difference list, and storing the drawing command of one band that is read out in the drawing command storage region; and
image data expanding means for converting the drawing command of one band stored in the drawing command storage region into image data and for expanding the image data in the image data expanding region.
To accomplish the object, the eighth printer host which according to the fifth or the sixth printer host, comprises:
a main storage unit in which are formed a spool file storing region storing the spool file, and the image data expanding region; wherein
the drawing command processing means comprises image data expanding means which successively reads out the drawing commands corresponding to the respective bands from the spool file stored in the spool file storage region of the main storage unit based on the drawing command difference list, converts the drawing command of one band that is read out into image data and expands the image data in the image data expanding region.
To accomplish the object, the fourth storage medium stores a program which expands a bundle of drawing commands of one page stored as a spool file into image data for each of the bands having a predetermined band width, the storage medium further stores the program which comprises the steps of:
forming a drawing command difference list by making reference to the spool file, wherein the start of drawing command representing the image is related to a band corresponding to the start position of the image and the end of the drawing command representing the image is related to a band corresponding to the end position of the image when the plural drawing commands are expanded into images; and
successively reading out the drawing commands corresponding to the respective bands from the spool file based on the drawing command difference list, converting the drawing command of one band that is read out into image data and expanding the image data in the image data expanding region.
To accomplish the object, the fifth storage medium according to the fourth storage medium, stores a program wherein:
the list-forming step forms a one-band drawing command list by making reference to the drawing command difference list, in which the drawing commands corresponding to one band are all related to the band in which the image expansion is to be carried out; and
the drawing command processing step makes reference to the one-band drawing command list to convert the drawing command of one band into image data and expands the image data in the image data expanding region.
According to the invention related to the fifth to eighth printer hosts and the invention related to the fourth and fifth storage media, employed is the drawing command difference list in which a start band and an end band of image represented by the drawing command are related, in order to call a desired drawing command from the spool file. Therefore, the quantity of data used for the list can be decreased compared to that of the conventional band-corresponded drawing command full list in which all of the drawing commands to be expanded in the respective bands are related to all of the band columns.