Force an image to an exact number of pixels

[Neofilm]

I'm trying to upload a 360 image to facebook that is

and facebook will not allow me to because

"Your 360 photo couldn't be uploaded due to restrictions on image dimensions. 360 photos should be less than 30,000 pixels in any dimension, and less than 128,000,000 pixels in total size."

I want to keep the image as large as possible. Is there a way to make photoshop export the image to meet these exact requirements?

[JJMack]

You image has 27,600x13,800= 380,880,000px which exceeds 128,000,000px so you need to reduce the number of pixels play with Image resize till the number come out to 128,000.000. seems to be 57.97% size.

[Neofilm · Accepted solution]

Thanks, I just played with the aspect ratios a few times until I came up with the perfect number and this worked! I was able to get it to the perfect size and it uploaded perfect...

[JJMack]

If you change the Asect ratio  You would distort the image.  You need to keep the aspect ratio the same and reduce the number of pixels. Width and height should be linked/constrained in the Image resize dialog.

16000x8000 are the same number I posted 57.97% width and height. Of the original size. the same aspect ratio 2:1

27600:13800 16000:8000 2:1  are 2:1 aspect ratios.

[Neofilm]

I know about constraining proportions. I never altered their ratios, I was just referencing that I played with the image size (while constraining proportions) and multiplied numbers using trial and error until I reached 128,000,000.

I really don't understand what you did and why you went by percent. For some reason you went into 12,800,000 which was not what I was after. Really what I was after was seeing if there's a way to tell photoshop or even lightroom what I want the end result to be and the software to just do the calculations for me. That was really what I was hoping for so in the future if I have to figure this out again I have a better workflow. I'm sure there's some equation I'm missing. But it ended up being pretty easy to simply toy with the size and multiply the two dimensions until I had what I needed.

You had the right idea but it wasn't executed properly it seems. You ended up with 1,600 by 8,000 and 12,800,000. I ended up needing it to be 16,000 by 8,000 for a total of 128,000,000. It seems that this would be a perfect job for the software, I was really hoping someone would have said it was and how... There's probably a website out there that has this equation... There's often been times when I have had to reduce an image size for a site and could have used such a feature...

[Trevor.Dennis]

Your aspect ratio is standard 1.5 or 6*4.

So if you want o maintain that, then it works out to

9236 pixels  X 13854 pixels = 127,955,544

If you didn't mind compromising the aspect ratio, you could closer, but I doubt it would show.