1. A method, performed by an electronic device with an image sensor, for capturing at least one image, the method comprising: capturing a preview image of a scene including at least one text object; identifying a plurality of text regions in the preview image; selecting a target focus region from the plurality of text regions; determining at least one brightness value associated with the target focus region; comparing the at least one brightness value to a threshold value; and adjusting at least one image capturing parameter for the image sensor based on the comparison.