Facsimile and static presentation processing – Natural color facsimile – Color separation
Reexamination Certificate
1999-06-17
2003-08-05
Lee, Cheukfan (Department: 2722)
Facsimile and static presentation processing
Natural color facsimile
Color separation
C358S509000
Reexamination Certificate
active
06603583
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reading method and apparatus, and particularly to an image reading method and apparatus, in which light is illuminated onto a developed photosensitive material, and based on the light transmitted through the photosensitive material, images recorded on the photosensitive material are read.
2. Description of the Related Art
There has been proposed in recent years a photographic processing method in which film images recorded on a developed photosensitive material such as a photographic film (hereinafter referred to merely as photographic film) are read in a state of being separated into component colors of R, G, and B and image data obtained by the reading is subjected to image processing including various corrections, and thereafter, an image is recorded on a recording material or is displayed on a display.
In an image reading apparatus used when film images are read using this type of photographic processing method, generally, light is irradiated on a film image and light transmitted through the film image is used to form an image, and further, a film image of a photographic film to be read is read, as image data comprised of a plurality of pixels, by an image sensor provided at an image-formation position, for example, a line CCD or an area CCD. The photographic film includes a negative film on which a negative image is recorded, and a positive film (a reversal film) on which a positive image is recorded.
In the image reading apparatus as described above, in order to correct variation of photoelectric transfer characteristics between every pixel of the image sensor, and further, in order to correct illumination unevenness, generally, light correction (shading correction) which allows correction of image data read by the image sensor for each pixel is performed.
In a conventional light correction method, based on image data obtained by reading a film image for adjustment whose entire image plane has a constant density, light correction data for each of pixels forming the image sensor is previously obtained and stored, and image data for each of pixels of a photographic film to be read is corrected in accordance with the above-described light correction data.
However, in the above-described light correction method, there is a problem that prior to reading of images on a photographic film to be read, it is necessary to read a film image for adjustment, for which operation is very complicated.
In order to solve the above-described problem, in the art disclosed in Japanese Patent Application Laid-Open (JP-A) No. 5-7296, at the time of reading images of a photographic film to be read, light correction data is acquired based on image data of a non-image region between image frames.
Further, in the art disclosed in Japanese Patent Application Laid-Open (JP-A) No. 10-75354, there is disclosed a method for acquiring light correction data without using a photographic film.
In the method disclosed in JP-A No. 5-7296, the light correction data is acquired from a non-image region between image frames on a photographic film to be read. For this reason, there are problems: it is difficult to reliably acquire light correction data when a space between image frames is narrow, and when a photographic film to be read is a positive film, the light correction data cannot be acquired from a non-image region of the positive film.
On the other hand, the method disclosed in JP-A No. 10-75354 does not use a photographic film for the purpose of saving labor at the time of acquiring the light correction data. Here, there is a problem that the color balance of R, G, and B of an image sensor at the time of acquiring the light correction data is remarkably different from the color balance of R, G, and B at the time of reading a photographic film, thereby resulting in that, when the image sensor has leakage sensitivity, light correction cannot be properly performed.
SUMMARY OF THE INVENTION
The present invention has been devised to solve the above-described problems, and an object thereof is to provide an image reading apparatus and method, in which light correction data can reliably be obtained accurately and without requiring a complicated operation.
In order to achieve the above-described object, an image reading apparatus according to a first aspect of the present invention comprises: a light source which emits light for illuminating a photosensitive material; an image sensor which reads an image recorded on the photosensitive material in a state of being separated into a plurality of pixels, and outputs the read image as image data; and adjusting means for adjusting the color balance of illuminating light emitted from said light source so that respective outputs of channels of said image sensor become substantially uniform both at the time of generation of light correction data and at the time of operation for light correction.
In accordance with the image reading apparatus and the image reading method relating to the first aspect of the present invention, both at the time of generation of light correction data and at the time of operation for light correction, the color balance of illuminating light emitted from the light source, which emits light for illuminating the photosensitive material to be read, is adjusted by the adjusting means so that respective outputs of channels (of red (R), green (G), and blue (B), or of cyan (C), magenta (M), and yellow (Y)) of the image sensor, the image sensor reading an image recorded on the photosensitive material in a state of being separated into, a plurality of pixels and outputting the read image as image data, become substantially uniform.
As described above, according to the image reading apparatus and the image reading method relating to the first aspect of the present invention, both at the time of generation of light correction data and at the time of operation for light correction, the color balance of illuminating light emitted from the light source is adjusted so that respective outputs of the channels of the image sensor become substantially uniform. Accordingly, respective states of the color balance of light emitted from the light source both at the time of generation of light correction data and at the time of operation for light correction can be made substantially uniform, and a complicated operation required when using a film image for adjustment of a constant density to generate light correction data becomes unnecessary. Further, even when a space between adjacent image frames of the photosensitive material is narrow, the light correction data can reliably be generated.
An image reading apparatus according to a second aspect of the present invention comprises: a light source which emits light for illuminating a photosensitive material; an image sensor which reads an image recorded on the photosensitive material in a state of being separated into a plurality of pixels, and outputs the read image as image data; a filter section including a negative-film color balance filter suitable for a negative film and a positive-film color balance filter suitable for a positive film, and disposed between said light source and said image sensor; light correction data generating means which generates light correction data based on data obtained by reading the positive-film color balance filter by said image sensor in a state without photosensitive material; and correction means which effects light correction for image data of the photosensitive material to be read based on the light correction data.
An image reading method according to a third aspect of the present invention comprises the steps of: generating in advance light correction data based on data obtained when, in a filter section which is disposed between a light source that emits light for illuminating a photosensitive material in a state of being separated into a plurality of pixels and outputs the read image as image data and which includes a negative-film color balance filter suitable for a negative fil
Fuji Photo Film Co. , Ltd.
Lee Cheukfan
Sughrue & Mion, PLLC
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