-- M module extracted from ITU-T J.249 (01/2010)
function [roi] = dll_default_vr (fn) % DLL_DEFAULT_VR % Return the default valid region for a given image size. % SYNTAX % [roi] = dll_default_vr (fn) % DESCRIPTION % This function takes fn, initialized in dll_video, and returns the default valid % region for that image size, 'roi'. The returned variable is also % a structure, with four elements, 'roi.top', 'roi.left', 'roi.bottom', % and 'roi.right'. [image_size.rows,image_size.cols] = dll_video('size',fn); if (image_size.rows == 486 | image_size.rows == 480) & image_size.cols == 720, % NTSC / 525-line roi.top = 19; roi.left = 23; roi.bottom = image_size.rows - 18; roi.right = image_size.cols - 22; elseif image_size.rows == 576 & image_size.cols == 720, % PAL / 625-line roi.top = 15; roi.left = 23; roi.bottom = image_size.rows - 14; roi.right = image_size.cols - 22; elseif image_size.rows == 720 & image_size.cols == 1280, % initialize maximum valid region. roi.top = 7; roi.left = 17; roi.bottom = image_size.rows - 6; roi.right = image_size.cols - 16; elseif image_size.rows == 1080 & image_size.cols == 1920, % initialize maximum valid region. roi.top = 7; roi.left = 17; roi.bottom = image_size.rows - 6; roi.right = image_size.cols - 16; else roi.top = 1; roi.left = 1; roi.bottom = image_size.rows; roi.right = image_size.cols; end