I have a basic logo that I would like to see with various sized pixels. I tried just shrinking the image and then zooming in but the reduction created reduced opacity pixels along the edges. I would like all the pixels to be solid.
The easiest way is to change the image to
Indexed Color instead of
Image > Mode. All transparent pixels will be removed and none will be created when the image is downsized.
Alternatively, you can duplicate and merge the downsized layer repeatedly. Even a pixel with 1/256th opacity will be opaque after 8 iterations.
Unless your shape only contains 90º angles, it will have semi-transparent edges. The reason is that pixels are square, so Photoshop tries to compensate for half-pixels with transparency. I made a little diagram to show what I mean by half-pixels:
The answer seems to easy too me so I guess I did not understood it well :)
But did you try: Filter > Pixel > Mosaic?