Marrissa Fretwell, now 17, from Norton Hill school in Bath, won the Digital Photography Competition with her challenging image of track-suited, hooded youths.
Her photo, which was entitled "Misunderstood", asked whether the youths were viewed unfairly. Her caption read: "I spent my lunchtime taking photos and not once were they the rude vandals people think."
The competition, themed on growth, was run by Canon UK. Pupils aged 11 to 16 entered in three categories - science and technology, culture and environment, and transport and travel.
Angela Mason-Warnes, from Canon, presented the winners with digital cameras and printers.
Other winners were Andrew Partington, from Wetherby high; Carly Wilson, from Thomas Hepburn school, Gateshead; and Megan O'Laughlin, of West Kirby grammar. They came first, second and third respectively in the science and technology category.
George Bright, from St Patrick's high in Manchester, Stefan Cave, from George Abbot school in Guildford and Carla Heasman, from Coombeshead College in Newton Abbot won prizes in the transport and travel category.
Hampton school art club and Ross Laws, from Biddick school in Washington, Tyne and Wear, won first and third prizes respectively in the culture and environment category.