Facsimile and static presentation processing – Natural color facsimile – Specific image-processing circuitry
Reexamination Certificate
1997-10-21
2001-06-05
Coles, Edward (Department: 2622)
Facsimile and static presentation processing
Natural color facsimile
Specific image-processing circuitry
C358S518000, C358S448000
Reexamination Certificate
active
06243174
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image processing device, a color printing device, an image processing method and a medium recording an image processing program accompanied by conversion of resolution and color conversion.
2. Description of the Prior Art
In printing a color image from an application in a computer system, conversion of resolution must be performed due to a difference in a resolution on a screen and a resolution in a printing device and data of RGB (red, green, blue) handled in a computer system is to be converted into data of CMY (cyan magenta, yellow) corresponding to ink colors of a printer.
In this case, the conversion of resolution is not indispensable since there are cases where both resolutions coincide with each other or where coincidence of the resolutions does not pose a problem. Therefore, as a procedure of processings, color conversion is executed after having resolutions coincide with each other.
According to the above-described conventional image processing device, when conversion is performed such that resolution is promoted, an original single pixel is converted into a plurality of pixels by which an operational amount of color conversion is increased since color conversion is carried out with respect to each pixel.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide an image processing device, a color printing device, an image processing method and a medium recording an image processing program capable of optimizing processings when conversion of resolution and color conversion are executed.
According to an image processing device accompanied by conversion of resolution and color conversion of the present invention, color conversion is performed in a state of low resolution, more specifically, the device includes resolution comparing means for comparing a resolution of color image data constituting pre conversion data with a resolution of color image data constituting post conversion data, resolution converting means for converting the resolutions between the color image data constituting the pre conversion data and the color image data constituting the post conversion data, color converting means for performing a color conversion between a color representing space of the color image data constituting the pre conversion data and a color representing space of the color image data constituting the post conversion data, and conversion order controlling means for executing the color conversion before or after converting the resolution on a side having a lower one of the resolutions, based on a comparison result of the resolution comparing means.
According to the present invention constituted as described-above, when the resolution converting means converts the resolutions between the color image data constituting the pre conversion data and the color image data constituting the post conversion data, the resolution comparing means compares the resolution of the color image data constituting the pre conversion data with the resolution of the color image data constituting the post conversion data and the color conversion is performed between the color representing space of the color image data constituting the pre conversion data and the color representing space of the color image data constituting the post conversion data on the side having a lower one of the resolutions before or after converting the resolutions under control of the conversion order controlling means. Needless to say, various methods can be substituted for the conversion order controlling means.
The essence of the present invention resides in performing color conversion in a state of low resolution when conversion of resolution and color conversion are executed in which when the original resolution is low and a conversion of enhancing the resolution is performed, the color conversion is performed before converting the resolution and when the original resolution is high and a conversion of lowering the resolution is performed, the color conversion is performed after converting the resolution.
Accordingly, the color conversion is performed in a state where pixels constituting the object of color conversion are few and accordingly the amount of processings can be reduced.
The resolution comparing means compares the resolution of the color image data constituting the pre conversion data with the resolution of the color image data constituting the post conversion data, where the means is not necessarily limited to a means for automatically outputting the comparison result and may be a means capable of determining on which side the resolution is low or high as a result, accordingly, the means may be a changeover switch by manual operation.
Various methods can be adopted with regard to methods of the resolution converting means for converting the resolutions between the color image data constituting the pre conversion data and the color image data constituting the post conversion data. Further, the resolution in this case corresponds to a number of pixels of rasterized dot matrix data in which before rasterizing as in meta file, in a state of a command file having no pixels, a number of objects to be subjected to color conversion corresponds to a number of commands designating color. Therefore, in this case, in a broad sense, the side having a lower one of the resolutions designates color image data where colors are designated by commands before rasterizing.
The color converting means performs color conversion between the color representing space of the color image data constituting the pre conversion data and the color representing space of the color image data constituting the post conversion data and various kinds of converting methods can be adopted. Generally, a color conversion table having component values of image data in a pre conversion color representing space is prepared and the color conversion table is referred. Naturally, in referring to the color conversion table, the operation can pertinently be changed as in utilizing interpolation calculation, utilizing a grey scale conversion in place of an interpolation calculation disclosed in Japanese Unexamined Patent Publication No. JP-A-7-30772 filed by the applicants or the like.
The conversion order controlling means may execute color conversion from the side having a lower one of the resolutions before or after converting the resolution degree as a result in which, for example, a procedure of converting the resolution after previously performing color conversion and a procedure of performing color conversion after previously converting the resolution may be prepared and either one of the procedures may be selected.
Various kinds of devices may be conceived as application examples where conversion of resolution and color conversion are executed. Therefore, it is an object of the present invention to provide a color printing device that is one application example.
According to an aspect of the present invention, there is provided a color printing device for printing a color image in accordance with a predetermined record density, in which raster data in accordance with the record density is formed from color image data constituting pre conversion data and color conversion is performed from a color representing space of the color image data constituting the pre conversion data to a color representing space of a print ink for printing with the record density, wherein a resolution of the color image data constituting the pre conversion data is compared with a resolution at the record density and the color conversion is performed before or after converting the resolutions, on a side having a lower one of the resolutions.
According to the color printing device printing dots at the predetermined record density, the raster data in accordance with the record density is formed from the color image data constituting the pre conversion data and the color conversion is performed from the color representing space of the color image data constituting t
Coles Edward
Pokrzywa Joseph R.
Seiko Epson Corporation
Sughrue Mion Zinn Macpeak & Seas, PLLC
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