Background: This research focused on the development, implementation and evaluation of a course on image-processing principles aimed at middle-school students. Purpose: The overarching purpose of the study was that of integrating the learning of subjects in science, technology, engineering and mathematics (STEM), and linking the learning of these subjects to the children's world and to the digital culture characterizing society today. Sample: The participants were 60 junior high-school students (9th grade). Design and method: Data collection included observations in the classes, administering an attitude questionnaire before and after the course, giving an achievement exam and analyzing the students' final projects. Results and conclusions: The findings indicated that boys' and girls' achievements were similar throughout the course, and all managed to handle the mathematical knowledge without any particular difficulties. Learners' motivation to engage in the subject was high in the project-based learning part of the course in which they dealt, for instance, with editing their own pictures and experimenting with a facial recognition method. However, the students were less interested in learning the theory at the beginning of the course. The course increased the girls', more than the boys', interest in learning scientific-technological subjects in school, and the gender gap in this regard was bridged. (Contains 1 table and 14 figures.)