Abstract: A representative color determining step is executed to determine, from image data, a representative color characterizing an image of a print, and positions of the representative color. A gray control color determining step is executed to determine, from the image data, a gray control color expressed in an achromatic color and positions of the gray control color. A reading step is executed to read an image of reference paper and an image of an actual print. Then, a calculating step is executed to carry out a comparative calculation of color data in the positions of the representative color of the image of the reference paper and color data in the positions of the representative color of the image of the print, and a comparative calculation of color data in the positions of the gray control color of the image of the reference paper and color data in the positions of the gray control color of the image of the print, to create control data for controlling ink feeding rates of a printing machine.

Abstract: A printed circuit board (11) is provided with a conductive pattern (P, R) and a through hole (H) thereon. Respective images of the conductive pattern and a through hole are photoelectrically read with an image reader (20). The conductive pattern image is magnified in size to obtain a magnified pattern image (PI.sub.m), while the hole image is magnified at different magnification factors to obtain magnified hole images (HI.sub.n, HI.sub.n-i). A ring image (RP) is defined by the difference of the magnified hole images. The overlapped region (WR) on which the ring image and the magnified pattern image overlap each other is then calculated, and a defect or an opening of the conductive pattern is detected by calculating the aperture angle (.theta.) of the overlapped image.

Abstract: An image reading method and apparatus therefor where charge-coupled devices (CCDs) and similar devices are utilized, especially for making adjustments to compensate for read-out position errors. The apparatus for reading images includes a circuit for generating an adjusted read-out address in order to obtain the desired image signals. The adjusted read-out address is obtained by using the actual data derived from scanning a sample chart with an image device, and computed reference data which is the same data that would be obtained if the sample chart is scanned with an ideal optical system. The sample chart comprises a series of lines provided at regular intervals. An apparatus and method for reading images inexpensively and easily is thus obtained, and which allows the reproduction of original images without distortion, color error or the like.

Abstract: An image reader includes a half mirror or the like disposed in an optical path extending from an input optical system to a CCD line sensor, and a linear light source disposed in an optical path branched out by the half mirror. The linear light source is located at a position equivalent to the CCD line sensor with respect to a document table, and is equal in length to an effective pixel region of the CCD line sensor. Light emitted from the light source is projected back to the document table. An effective image reading area is displayed on the document table by relatively moving the document table and linear projected image in a sub-scanning direction. The linear light source is rotatable in accordance with a desired setting angle of an original. Consequently, an inclined image is projected back to the document table to serve as a guideline for setting the angle of the original.