pythoncssimagecolorstuples

Convert RGB color to English color name, like 'green' with Python


I want to convert a color tuple to a color name, like 'yellow' or 'blue'

>>> im = Image.open("test.jpg")
>>> n, color = max(im.getcolors(im.size[0]*im.size[1]))
>>> print color
(119, 172, 152)

Is there a simple way in python to do this?


Solution

  • It looks like webcolors will allow you to do this:

    rgb_to_name(rgb_triplet, spec='css3')

    Convert a 3-tuple of integers, suitable for use in an rgb() color triplet, to its corresponding normalized color name, if any such name exists; valid values are html4, css2, css21 and css3, and the default is css3.

    Example:

    >>> rgb_to_name((0, 0, 0))
    'black'
    

    it is vice-versa-able:

    >>> name_to_rgb('navy')
    (0, 0, 128)
    

    #To find the closest colour name:

    However webcolors raises an exception if it can't find a match for the requested colour. I've written a little fix that delivers the closest matching name for the requested RGB colour. It matches by Euclidian distance in the RGB space.

    import webcolors
    
    def closest_colour(requested_colour):
        min_colours = {}
        for key, name in webcolors.CSS3_HEX_TO_NAMES.items():
            r_c, g_c, b_c = webcolors.hex_to_rgb(key)
            rd = (r_c - requested_colour[0]) ** 2
            gd = (g_c - requested_colour[1]) ** 2
            bd = (b_c - requested_colour[2]) ** 2
            min_colours[(rd + gd + bd)] = name
        return min_colours[min(min_colours.keys())]
    
    def get_colour_name(requested_colour):
        try:
            closest_name = actual_name = webcolors.rgb_to_name(requested_colour)
        except ValueError:
            closest_name = closest_colour(requested_colour)
            actual_name = None
        return actual_name, closest_name
    
    requested_colour = (119, 172, 152)
    actual_name, closest_name = get_colour_name(requested_colour)
    
    print("Actual colour name:", actual_name, ", closest colour name:", closest_name)
    

    Output:

    Actual colour name: None , closest colour name: cadetblue