Image inspection apparatus in plate making process and image inspection method in plate making process

An image inspection apparatus in a plate making process in which a proof sheet comprising a recording of an image is used as a reference, and any one of an original plate film being corrected with reference to said proof sheet, a press plate obtained by performing exposure/development through said original plate film, and another proof sheet prepared from said press plate is used as an object, said image inspection apparatus is used for comparing said reference with said object and inspecting said object, said image inspection apparatus comprising:

• a) holding means capable of holding said reference and said object;
• b) illumination means for illuminating said reference and said object being held by said holding means,
• c) image pickup means for receiving light from a subject to be read, said subject being one of aid reference and said object for picking up an image on said subject to be read when said subject to be read is held by said holding means while receiving light, and for receiving light from another subject, said other subject being the other of said reference and said object and picking up an image on said other subject to be read when said other subject to be read is held by said holding means, said image pickup means is adapted to pick up an image on each of said subject and other subject to be read as a color image, reference and object images being images on said reference and said object are color images respectively,
• d) an optical system for guiding said light from either said subject to be read or said other subject to be read to said image pickup means;
• e) difference detection means for detecting differences between said reference and said object by comparing said images on said reference and said object with each other based on image information output from said image pickup means and detecting mismatching portions;
• f) output means for displaying a detection result by said difference detection means;
• g) color component adder means for obtaining color component sums by adding up a plurality of color components every pixel as to said reference and object images;
• and
• h) optimum displacement deciding means for relatively displacing said reference and object images in various ways for determining matching degrees of spatial distributions of said color component sums of respective said pixels of said reference and object images in respective ones of said displacements, and deciding that a relative displacement having maximum said matching degree is an optimum displacement, said difference detection means comparing said reference and object images with each other in a state displacing said reference and object images by said optimum displacement for detecting differences between said reference and object images.

An image inspection apparatus in a plate making process in which a proof sheet comprising a recording of an image is used as a reference, and any one of an original plate film being corrected with reference to said proof sheet, a press plate obtained by performing exposure/development through said original plate film, and another proof sheet prepared from said press plate is used as an object, said image inspection apparatus is used for comparing said reference with said object and inspecting said object, said image inspection apparatus comprising:

• a) holding means capable of holding said reference and said object;
• b) illumination means for illuminating said reference and said object being held by said holding means,
• c) image pickup means for receiving light from a subject to be read, said subject being one of aid reference and said object for picking up an image on said subject to be read when said subject to be read is held by said holding means while receiving light, and for receiving light from another subject, said other subject being the other of said reference and said object and picking up an image on said other subject to be read when said other subject to be read is held by said holding means;
• d) an optical system for guiding said light from either said subject to be read or said other subject to be read to said image pickup means;
• e) difference detection means for detecting differences between said reference and said object by comparing said images on said reference and said object with each other based on image information output from said image pickup means and detecting mismatching portions;
• and
• f) output means for displaying a detection result by said difference detection means, said output means outputs a mismatch mark indicating a mismatch onto an output paper, said mismatch mark corresponds with a mismatch position detected by said difference detection means.

An image inspection apparatus in a plate making process for performing image inspection by comparing two image data in different stages of said plate making process with each other, said image inspection apparatus comprising:

• a) means for comparing first digital image data with second digital image data and providing a comparison result;
• and
• b) means for outputting said comparison result,
• said first digital image data being selected from:
• digital image data being obtained in a stage immediately before recording on an image recording medium, and
• digital image data being obtained by reading an image recorded on an image recording medium,
• said second digital image data being selected from:
• digital image data obtained in a stage immediately before recording on an image recording medium, and
• digital image data being obtained by reading an image recorded on an image recording medium.

An image inspection method in a plate making process for performing image inspection by comparing two image data in different stages of said plate making process with each other, said image inspection method comprising steps of:

• a) comparing first and second digital image data with each other and providing a comparison result;
• and
• b) outputting said comparison result,
• said first digital image data being selected from:
• digital image data obtained in a stage immediately before recording on an image recording medium, and
• digital data being obtained by reading an image recorded on an image recording medium,
• said second digital image data being selected from:
• digital image data being obtained in a stage immediately before recording on an image recording medium, and
• digital image data being obtained by reading an image recorded on an image recording medium.