An image processing apparatus according to embodiments obtains a variance value of signal values of pixels included in a predetermined region of the read image read from an original, and compares the obtained variance value with a threshold value for determining whether the read image has a halftone dot region. Furthermore, the present image processing apparatus, upon determining that the read image includes a halftone dot region in accordance with the result of this comparison, executes a first removal process for removing the reflection of an image of one surface of an original when reading the other surface, and executes a second removal process otherwise.