An image processing apparatus, comprising:
- reading means for reading a document sheet line by line to derive image data, said reading means storing one line of image data at a predetermined storage time,
- recording means for recording the image data on a record sheet line by line, said recording means recording one line of image data at a recording time longer than the predetermined storage time;
- and
- correcting means for correcting the image data read by said reading means based on a difference between the predetermined storage time and the recording time,
- wherein said correcting means corrects the image data read by the reading means by changing the predetermined storage time to synchronize a reading process of said reading means for one line with a recording process of said recording means for one line.