Save in PNG format
You can use the Save As command to save RGB, Indexed Color, Grayscale, and Bitmap mode images in PNG format.
Choose File Save As, and choose PNG from the Format menu.
Select an Interlace option:
None
Displays the image in a browser only when download is complete.
Interlaced
Displays lowresolution versions of the image in a browser as the file downloads. Interlacing makes download time seem shorter, but it also increases file size.
Click OK.