Abstract
Children need entertainment that at the same time helps develop their mental skills and creative thinking. Coloring applications often attract them as they contain coloring and drawing. However, the majority of them are difficult to use for children and can have a fixed set of available coloring pages, which can make it uninteresting after the child have tried them all. This paper presents a new coloring mobile application that allows children to be creative and make their own coloring pages on-the-go by taking pictures of what they want to color. In this application, a child snaps a photo using the mobile device's camera, which is then transformed into a coloring page and provided with tools to color and save the new creation in the mobile device. The transformation is done using image processing techniques: image smoothing and edge detection. The application provides three difficulty levels for the children: easy, medium, and advanced. It uses automatic parameter selection for each level that is adaptive to the input image. Evaluation of the parameter selection method proved its suitability for the application. User acceptance test was performed for the application which showed high successful completion rates and user satisfaction.