1. Field of the Invention
The present invention relates to an image processing method and an image processing apparatus for reading original images and performing an image output by executing processing to the read images, and more particularly to an image processing method and an image processing apparatus capable of reading originals by plural reading systems.
2. Related Background Art
Conventionally, in a digital copying machine or a facsimile apparatus, a light beam is irradiated to an original by lighting a light source and reflection light reflected from the original is read to convert it into digital data, then various image processing are executed to the digital data, and an image output has been performed.
Image reading systems in case of reading original images are roughly classified into two systems. One is an image reading system of reading all parts on an original by fixing the original and moving the light source (hereinafter, to be referred as fixing original reading). The other is an image reading system of reading all parts on the original by fixing the light source and shifting the original (hereinafter, to be referred as shifting original reading).
According to a conventional art, in an image processing apparatus capable of using both of the fixing original reading and the shifting original reading, in spite of difference in the image reading system, images were output by always executing the same image processing.
In a case where minute dirt or dust is lain between the light source and the original, since the light source moves in case of the fixing original reading, the dirt is momently lighted by the light source and influence by the dirt for the read image is appeared in sight by only a minute dot. However, in case of the shifting original reading, since the relationship between the light source and the dirt is in a fixed state, the light source is always to light the dirt and the influence by the dirt for the read image is appeared in sight by a line or a plane.
If images are output by executing the same image processing to the images which were read by reading systems of the fixing original reading and the shifting original reading, the output image in case of using the shifting original reading is more influenced by the dirt as compared with the output image in case of using the fixing original reading. That is, in image processing, edge emphasis processing is generally executed by using a digital filter. However, dirt information is also emphasized by the edge emphasis processing. Particularly, in the shifting original reading, there occurred a drawback that the influence by the dirt for the output image is more increased.
The present invention is to eliminate the above drawback, and an object thereof is to provide an image processing method and an image processing apparatus which can reduce influence by the dirt in case of shifting original reading by varying edge emphasis degree in edge emphasis processing for image data which was read in accordance with a fact that an original reading system is fixing original reading or the shifting original reading.
In order to achieve the above object, the present invention provides an image processing method comprising:
a reading step of reading original images;
a processing step of executing edge emphasis processing to image data from the reading step; and
a discrimination step of discriminating if an original reading system in the reading step is fixing original reading for reading an original image by fixing an original or shifting original reading for reading the original image by shifting the original,
wherein the processing step varies edge emphasis degree in the edge emphasis processing for image data read in accordance with a discrimination result obtained in the discrimination step.
Further, the present invention provides an image processing apparatus comprising:
a reading means for reading original images to output image data; and
a processing means for executing edge emphasis processing to image data from the reading means,
wherein the reading means reads originals by any one of original reading system of fixing original reading for reading an original image by fixing an original or shifting original reading for reading the original image by shifting the original, and
the processing means varies edge emphasis degree in the edge emphasis processing for the image data which was read in accordance with a fact that the original reading system is the fixing original reading for reading the original image by fixing the original or the shifting original reading for reading the original image by shifting the original.
Further, another object of the present invention is to provide an image processing method and an image processing apparatus which can reduce the influence by the dirt in case of the shifting original reading by executing the edge emphasis processing of which the edge emphasis degree is lower than that of the fixing original reading, in a case where the original reading system is the shifting original reading.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.