catch someone's attention
US /kætʃ ˈsʌm.wʌnz əˈten.ʃən/
UK /kætʃ ˈsʌm.wʌnz əˈten.ʃən/

1.
to make someone notice you or something
:
•
He tried to wave his hand to catch her attention.
•
The bright colors of the painting immediately caught my attention.