Having difficulty with Pointillize

[Babak23213247osmy]

I am new to Photoshop and I am having difficulty making an impressionistic photo.  I have a landscape photo and I have sized the image to:  Ht 720 with a resolution of 150 pixels/inch.  I also opened a Monet Painting in a new tab and color matched it.  However, when I try to go to Pixelate filter, the Pointilize filter is grayed out.  I am using a Macbook Pro with a M1 chip.

Thank you

[Peru Bob]

I've moved this from the Using the Community forum (which is the forum for issues using the forums) to the Photoshop forum so that proper help can be offered.

[Chuck Uebele]

What file type are you using and what is the color space: RGB jpg?

[Babak23213247osmy]

Hello,

I purchased a photo from iStock photos.  It is a jpg.   Under Mode tab it indicates it is RGB.