[software] fix: main_openMVG2openMVS support grayscale images (#1709)
[software] fix: main_openMVG2openMVS support grayscale images (#1709)


openMVG/openMVG,openMVG/openMVG,openMVG/openMVG,openMVG/openMVG,openMVG/openMVG