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Participant
October 8, 2019
Answered

Photoshop 32 bits PNG

  • October 8, 2019
  • 1 reply
  • 2603 views

Hello,

I have a file that is 300 DPI 4000X4000 pixels 32-bit. I want to export it in PNG-32 (or even 24!). I do "export as" export PNG format without ticking the box 8-bit and when I bring back my PNG file in Photoshop, it is 8-bit! Even when I see it in Bridge, it tells me that this file is 8-bit. I have watched several forums since yesterday and there, I am totally without resources ... Thank you for your help!

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Correct answer Test Screen Name

I think you are mixing up two different kinds of "32 bit", not surprising really, it's very confusing.

 

I assume your current image is RGB and shows Image > Mode > 32 bit. This is a special kind of working, not stored in ordinary image files. This is 32 bit per component - 32 bits for red, 32 bits for green and 32 bits for blue. A total, in fact, of 96 bits for each pixel.

 

Now, when people talk about 32 bit PNG what they mean is it is 32 bits for each pixel: 8 each for red, green and blue and another 8 for "alpha". 24 bit PNG is the same without the alpha. So, if you export to PNG your 32 bits for each component is turned into 8 bits, and when you reopen it that's what you get. This is plenty for delivering graphics to the web. When you reopen a 24 or 32 bits (per pixel) PNG in Photoshop, you'll correctly see that you now have an 8 bit (per component).

 

Of course, you lose lots of info from your original file, which is why we always save as PSD for editing later.

 

1 reply

Test Screen NameCorrect answer
Legend
October 8, 2019

I think you are mixing up two different kinds of "32 bit", not surprising really, it's very confusing.

 

I assume your current image is RGB and shows Image > Mode > 32 bit. This is a special kind of working, not stored in ordinary image files. This is 32 bit per component - 32 bits for red, 32 bits for green and 32 bits for blue. A total, in fact, of 96 bits for each pixel.

 

Now, when people talk about 32 bit PNG what they mean is it is 32 bits for each pixel: 8 each for red, green and blue and another 8 for "alpha". 24 bit PNG is the same without the alpha. So, if you export to PNG your 32 bits for each component is turned into 8 bits, and when you reopen it that's what you get. This is plenty for delivering graphics to the web. When you reopen a 24 or 32 bits (per pixel) PNG in Photoshop, you'll correctly see that you now have an 8 bit (per component).

 

Of course, you lose lots of info from your original file, which is why we always save as PSD for editing later.

 

Participant
October 8, 2019
Thank you so much for these precisions !!! Indeed, it's easy to get lost in this world of PNG! 😉 This PNG is for printing clothes, so I want to make sure the picture is clear! So, if I understand correctly, I have to put my file in Image> Mode> 8 bits and after I export for the web in PNG-24 and the file will be ok and of good quality? The 8-bit that appears in the info next to my file when I bring it back to Phoptoshop is simply to tell me that each layer (R-G-B + Alpha) on 8-bit each? Thank you in advance!
davescm
Community Expert
Community Expert
October 8, 2019

No need to use Image mode to change the bit depth. The "export as" process will change the bit depth for you. The rest you have picked up correctly

Dave