Radiant energy – Infrared-to-visible imaging
Reexamination Certificate
2000-05-11
2004-07-20
Epps, Georgia (Department: 2873)
Radiant energy
Infrared-to-visible imaging
C250S341100, C250S339050, C250S341500, C358S448000, C358S474000
Reexamination Certificate
active
06765206
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reading method for reading the image of transmission originals such as a developed photograph film, an image reading apparatus thereof, and a memory medium for storing a control program to control the image reading apparatus.
2. Related Background Art
In a conventional image reading apparatus (film scanner), transmission originals such as a micro film and a photograph film is irradiated by a lighting optical system from the back of the transmission originals and the transmitted light is projected to the image forming plane of a photoelectric conversion element via a projection optical system to form an image, thereby performing photoelectric conversion by the photoelectric conversion element to convert information of the transmission original into electrically.
In such the conventional apparatus, however, foreign matters adhering to the lighting optical system and projection optical system and foreign matters and flaws on the transmission original appear as black spots on the read image data, and as a result there arises a problem that the image is deteriorated.
FIGS. 34A and 34B
are schematic diagrams showing the influence of the above-described foreign matters and flaws to the image data and output image,
FIG. 34A
shows that the transmission original is a reversal film, and
FIG. 34B
shows that the transmission original is a negative film.
In
FIG. 34A
, the image (positive image) of the reversal film on which an object is photographed is read by a scanner (film scanner) as an image reading apparatus, and the read image signal is subjected to gamma correction, and outputted as the positive image visible to human eyes.
Moreover, in
FIG. 34B
, the image (negative image) of the negative film on which the object is photographed is read by the scanner (film scanner) as the image reading apparatus, the read image signal is subjected to reversal processing, and subsequently to the gamma correction (image processing), and is outputted as the positive image visible to human eyes.
As shown in
FIGS. 34A and 34B
, whichever the transmission original is the reversal film or the negative film, the foreign matters/flaws appear as the black spots on the image signal and output image (positive image), when the transmission original is converted to the image signal and read by the scanner (film scanner) as the image reading apparatus.
As a result, for the reversal film, as shown in
FIG. 34A
, since the image signal is subjected to the image processing such as the gamma correction and outputted onto an output apparatus such as a printer as it is, the influences of the foreign matters/flaws appear as the black spots on the output image (positive image) as they are.
On the other hand, for the negative film, as shown in
FIG. 34B
, since the image signal read by the scanner is subtracted from the image signal read at a full level to convert the negative image to the positive image, the influences of the foreign matters/flaws appear as white luminous spots on the output image (positive image).
To solve the problem, the transmittance characteristic of the transmission original to infrared light has been noted, and there has already been proposed an image reading apparatus (film scanner) for detecting only the foreign matters/flaws causing the image deterioration as described above, by the infrared light transmitted through the transmission original, and applying the correction to the read image data with the information of the detected foreign matters/flaws.
FIG. 35A
shows a visible image reading system, and
FIG. 35B
shows an infrared image reading system. Moreover, in the drawings, numeral
31
denotes an original,
32
denotes an image plane as a light receiving element such as CCD, and
33
denotes an image forming lens for forming the image of the original
31
on the image plane
32
.
In
FIG. 35A
, in order to read the image of the original
31
, the image of the original
31
irradiated with visible light is read in an appropriate image forming state. On the other hand, in
FIG. 35B
, the infrared light is radiated to the image of the original
31
to read the defects such as the foreign matters and flaws on the original.
In this manner, the defects in the image information read by the visible light are corrected by the range information of the foreign matters and flaws on the original read by the infrared light.
One example is disclosed in Japanese Patent Publication No. 7-97402 (hereinafter referred to as a first related art), Japanese Patent No. 2559970 (hereinafter referred to as a second related art) and Japanese Patent Publication No. 6-78992 (hereinafter referred to as a third related art).
In the first related art, the image information around the pixel recognized as the foreign matter/flaw is appropriately selected to perform data correction.
Moreover, in the second related art, in addition to the image correction from the image data around the pixel recognized as the foreign matter/flaw, the image correction is also performed based on the infrared-light data of the area of the pixels recognized as the foreign matters/flaws, and further a plurality of image correction methods are adaptively used in accordance with the level of the infrared-light data.
Furthermore, in the third related art, in order to correct the positional deviation of the image forming plane by the wavelength difference between the visible light and the infrared light, the optical path length can be changed for each light to be formed into the image.
However, in the related art, when the optical path length is changed to correct the positional deviation of the image forming plane, a relative ratio of a distance between a transmission original surface and an optical system main point position to a distance between the optical system main point position and the image forming plane changes, then the visible light is different from the infrared light in image magnification, and it is disadvantageously difficult to accurately grasp the position of the foreign matter/flaw. Thus, the correction of the foreign matter/flaw is incorrect, and the image grade is sometimes deteriorated by performing the correction processing.
Moreover, in the related art described above, when the foreign matter/flaw area is grasped by the infrared light, and if the image data is extracted with the same resolution as that of the scan by the visible light, the time or memory required for extracting the image data is simply doubled, and further the time required for correcting the image data or the memory capacity is also necessary by the considerable amount, thereby causing a problem that there is a difficulty in operationality for performing the correction processing of the foreign matter/flaw.
Furthermore, in the related art described above, since the correction of the foreign matter/flaw on the transmission original is performed in the system, that is, in the system controller, an operator cannot recognize the progress. The operator simply needs to see the corrected image with respect to the image of the transmission original having the foreign matter/flaw to recognize that the correction has been performed. Moreover, since the foreign matter/flaw correction system is not universal for all cases, and conversely the image is sometimes deteriorated by performing the correction, the operator needs to recognize the progress also to judge whether or not to correct the foreign matter/flaw. In the related art, however, the operator cannot easily compare or recognize the foreign matter/flaw correction effects, and it is disadvantageously difficult to easily select an image from an image finally obtained before performing the foreign matter/flaw correction and an image after such the performing.
SUMMARY OF THE INVENTION
The present invention has been developed in consideration of the above-described problems of the related arts, and a first object thereof is to provide an image reading method and apparatus in which the position of a foreign matte
Sugiyama Miho
Wada Hiroyuki
Epps Georgia
Hasan M.
Morgan & Finnegan , LLP
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