c++ - Image processing with openCV, color change -

i doing image processing , have black shape on white image. use findcontours() need white shape on black image.

1. is there way change opencv settings track black shapes on white background instead ?
2. i managed find white part of image using inrange() change other color, change black part white, , again first part black using inrange(). there easier way convert black white , white black on image @ same time ?

starting binary_image of type cv_8uc1:

1. you can use binary_not (as suggested @zdar):

   binary_not(binary_image, binary_image); 

2. invert values aritmtetic operation (as suggested @sunreef):

   binary_image = 255 - binary_image; 

3. or use not logical operator ~.

   binary_image = ~binary_image; 

   this can nice shortcut if need invert values particular function, e.g.:

   findcontours(~binary_image, ... );