How to count unique/ distinct visible values in a filtered column, with considering blank cells?

As such references I had found, those are not covering "assuming blank cells same as non-blank ones" matter.

I had found this array formula: (Ref: extendoffice.com)

=SUM(IF(FREQUENCY(IF(SUBTOTAL(3,OFFSET(D2,ROW(D2:D22)-ROW(D2),,1)), IF(D2:D22<>"",MATCH("~"&D2:D22,D2:D22&"",0))),ROW(D2:D22)-ROW(D2)+1),1))

Any guides are appreciated.

Update

F22 result of calculating for Table1[Column1]

G22 result of calculating for Table1[Column2]

H22 result of calculating for Table1[Column3]

I want the Formula returns: G22=4 & H22=1

Note: My table has filtered range and I calculating visible values.

In the formula you quote the SUBTOTAL part is used to only consider visible cells.......but it also ignores blanks, so if you want to include blanks as another distinct value to be counted that's a problem.

Do you have any column that you know will be fully populated (e.g. column A)? If so you can base the SUBTOTAL part on that column and the counting distinct on the actual column in question, e.g. assuming A2:A22 will always be fully populated try this version to count distinct values in D2:D22 (including blanks):

=SUM(IF(FREQUENCY(IF(SUBTOTAL(3,OFFSET($A2,ROW($A2:$A22)-ROW($A2),,1)),MATCH("~"&D2:D22,D2:D22&"",0)),ROW(D2:D22)-ROW(D2)+1),1))

confirmed with CTRL+SHIFT+ENTER