An image sensor is wieldy used in many fields, including medical field and security device. Specifically, the image sensor is most widely used in digital camera and mobile phone. The digital camera and the mobile phone requires capture image of higher resolution and higher quality. However, a preview size of the mobile phone or digital camera requires a small size because of a display limitation. Therefore, a function of reducing an image size or magnifying a specific portion of the picture is essential in the image sensor. Accordingly, there is provided an image sensor with a scaler. The image sensor with the scaler can arbitrarily adjust a size of an image without any additional scaling chip.