query_color — Query all color names displayable in the window.
query_color returns the names of all colors that are usable for region output (disp_region, disp_polygon, disp_circle, etc.). On a b/w screen query_color returns 'black' and 'white'. These two “colors” are displayable on any screen. In addition to 'black' and 'white' several gray values (e.g. 'dim gray') are returned on screens capable of gray values. A list of all displayable colors is returned for screens with color lookup table. The returned tuple of colors begins with b/w, followed by the three primaries ('red','green','blue') and several gray values. query_all_colors(::WindowHandle:Colors ) returns a list of all available colors. For screens with truecolor output the same list is returned by query_color. The list of available colors (to HALCON ) must not be confused with the list of displayable colors. For screens with truecolor output the available colors are only a small subset of the displayable colors. Colors that are not directly available to HALCON can be chosen manually with set_rgb or set_hsi. If colors are chosen that are known to HALCON but cannot be displayed, HALCON can choose a similar color. To use this feature, set_check(::'~color':) must be set.
open_window(0,0,-1,-1,'root','invisible','',WindowHandle) query_color(WindowHandle,Colors) close_window(WindowHandle) fwrite_string (FileHandle, ['Displayable colors: ',Colors])
query_color returns 2 (H_MSG_TRUE), if the window is valid. Otherwise an exception is raised.
query_all_colors, set_color, disp_region, open_window