| 摘要 |
PURPOSE:To reduce the granular noise of a silver salt film and to improve the SN ratio of a read image by providing an image reader with a granular noise reducing function. CONSTITUTION:Granular noise is detected by using a near infrared-ray area or an infrared-ray area other than an optical wavelength area 400 to 700nm to be necessary information for a color image and more than 750nm capable of detecting only the granular noise at a level close to a visual area and the detected granular noise data are subtracted from the color image data to reduce the granular noise. Thereby, the image reader has a subtractor 6 for subtracting the granular noise data from the image data of an image 1 to be read out and outputting the subtracted result and a high pass filter (HPF) 7 for cutting an image data component leaked at the time of detecting the granular noise. Consequently, the SN ratio of the read image can be improved. |
