Turning photo – colored dot pattern photoshop effect

Step:1

Open a document in Photoshop.Duplicate the background layer.Add a new layer above it and fill with black color.

Step:2

Add a Mosaic filter with the value of 20 cells in Photoshop.Add a Layer mask in it.

Step:3

Open a new document with height and width of 20 pixels.Draw a circle and fill with black color. Then invert the colors.Now the background will be in black color and circle will be in white.

Step:4

Then go to edit -> define pattern and define as circle.then close this document.

Step:5

Coming to the photo document go to edit and fill the layer mask with circle pattern. Add a hue/saturation above this layer.