Code reader with extended reading range

An image based code reader comprises an image sensor. The image sensor is configured to acquire an image of a code. Additionally, the image based code reader includes a lens configured to project an image scene including the code onto the image sensor, the lens comprising a variable optical power that controls a focus distance of the image based code reader. The image based code reader further includes a processor operatively coupled to the image sensor and the lens. The processor is configured to acquire the image of the code using only pixels located within a region of interest of the sensor, and a size of the region of interest is selected based on the focus distance of the reader.