WITH 13 categories this year, the 17th Hongkong International Film Festival will be an arthouse filmgoer's delight. Festival manager Ms Angela Tong, who announced this year's programme on Friday, said this year's screenings focus on independent film-makers whose work might otherwise never be shown outside their home countries. Hongkong's alternative film audience generally gets a good dose of high quality ''art'' films at the festival - ''usually good movies and prize winners with big names'' - but special categories were needed ''to promote unknowns'', Ms Tong said. Director John Cassavetes, a seminal figure in American independent cinema, has been allotted a special tribute. His 1978 film Opening Night, featuring wife Gena Rowlands, is one of the festival's opening films while eight more of his highly original and critically acclaimed works complete the retrospective. The category entitled The Zone will be particularly challenging to a Hongkon g audience reared on a mainstream diet. The eight offerings in this category take on the accepted modes of film presentation and subject matter. These include ''marginal'' films such as I've Heard the Ammonite Murmur by Isao Yamada - described as the first ''minimal-entertainment-art film ever in Japan'' - which dispenses with dialogue and plot development in deference to imagery. Another, Passages, depicts the conditions of the handicapped. Acted and directed by disabled people, it is said to be honest to the point of becoming painful. The Room is another in the category. Its plot is thus described: ''A middle-aged killer is looking for 'the room': a kind of pre-development utopia. He goes room-hunting with an expressionless real estate agent, but all he finds are the ruins of Tokyo.'' As Ms Tong said, these experimental films ''may have a single subject matter that is not interesting or dramatic in a commercial sense''. Another genre which usually falls foul of Hongkong's film scene is the documentary. The Truth or Dare category brings together 12 documentaries from East and West. Included is a chillingly relevant film called Liberators Take Liberties - War, Rape and Children which depicts the story of the Red Army's march into Germany towards the end of World War II. As with the Cassavetes retrospective, festival organisers have included a five-film tribute to a renowned documentary maker - Shinsuke Ogawa, who died last year. Two other ''specials'' this year are a focus on animation - with a particularly rich and politicised input from Iran - and the Asian Cinema category, from which the comic features For Fun by Ning Ying and Ang Lee's The Wedding Banquet open and close the festival respectively. For the first time Hongkong's independent short film competition winners have been added to the international cast list. Their inclusion is designed to promote home-grown films outside the commercial market. Meanwhile, the only cancellation in this year's festival so far is Chen Kaige's Farewell to My Concubine. The film is to be entered for this year's International Film Festival at Cannes, which prohibits prior showing at any other festival. The Hongkong International Film Festival runs from April 8-23. All tickets are $38. Postal bookings and reservations by registered patrons on 734-9011 can be made until March 11. Counter bookings start on April 2 and telephone reservations from April 3. Call 734-9009 for details.