1. A method for detecting texts included in an image, comprising steps of: (a) an apparatus detecting or allowing other device to detect at least one text candidate in an inputted image, if acquired, by referring to feature values of pixels in the inputted image; (b) the apparatus classifying or allowing other device to classify (i) the detected text candidate as a strong text or a non-strong text by referring to a comparison result between a first threshold value and a first feature value of at least one pixel selected within a corresponding region where the detected text candidate is included or a value converted from the first feature value, and (ii) the text candidate classified as the non-strong text as a weak text or a non-text by referring to a comparison result between a second threshold value and a second feature value of at least one pixel selected within a corresponding region where the text candidate classified as the non-strong text is included or a value converted from the second feature value; and (c) the apparatus determining whether to classify or allow other device to classify the weak text as the strong text by referring to information on the strong text and information on the weak texts; wherein, at the step of (c), the apparatus reclassifies or allows other device to reclassify the weak text as strong text or non-text based on at least one degree of similarity between one or more respective characteristics of the weak text and the strong text.