It’s ppi, not dpi.
When the file is 300ppi the resulting PNG-24 are 300ppi for me, so I’m not sure I understand your problem.
How are you trying to do tha?t. If you get the layers bound. You can copy the layer to the clipboard open a new document with its correct pixel width and pixel height with a 300dpi resolution with a name like the "layer name, layer stack level and timestamp". Then paste in the clipboard save and close the new document.
Export may not be setting any DPI value. If you open a document without a DPI setting in Photoshop. Photoshop will default the document setting to 72dpi. Photoshop need a some dpi setting for proper operation. There is no resize there is just a value set for DPI resolution. Pixels are not altered.
Sorry, yes It is PPI. I have basically taken some digital photo's of polaroids and edited them a little in photoshop (adding a drop shadow etc) they are all at full resolution. I am trying to export them as High Res PNG'S so I can then place them into an indesign document for printing. Does that make sense? Thank you!
I do not use Export except for rendering Video and "Save for Web". So I do not know how Adobe implemented Export quick png. Png files, are normally use on the web and DPI is meanless there because displays do not support various resolutions. They run at a single resolution, their native single resolution. What is important is the number of pixels. Therefore, Adobe may not have set a resolution value in the saved png file. If a file has no DPI resolution, if you open it in Photoshop, Photoshop will assign it to have a 72DPI resolution. Pixels are not changed. Photoshop needs the image to have some resolution setting for proper operation.
You can set a document resolution without resampling all that changes is the DPI setting. The Image will print a different size because of the change in pixel density. So in a Photoshop action, you can set the document resolution you want. Toggle all other visible layer visibility off. Then use "save as" png to save the png file with the resolution you need. Then toggle the other layer visibility back to what there were.
Again what is important is the number of pixels. A document has a single DPI resolution. All Layers in a document have that resolution. So If you paste or place an image with a 72doi resolution or and image with no resolution into a 300DPI document the pixels in the document layer will have document DPI resolution. Pixels again are not changed.
I'm having the same problem was hoping to find an answer. When I create a letter size page at 300 dpi and export all layers to png. The Pngs are 72 dpi. There must be a place at change the setting but I can't find it.
Why not use menu File>Savs AS and save png files. Quick Exoprt as PNG and Export AS are relatively new Photoshop features and may not be perfect yet. Save AS has been working for years and years.
Comparing the metadata, I believe that “save as” uses non-standard extras/extensions to the specification to make PNG behave in Adobe apps such as InDesign in a similar fashion to other images such as TIFF, while the “export as” feature creates stripped down files that are lacking these metadata extras/extensions (so even though the pixel dimensions are the same, the PPI and print size metadata are handled differently in other apps).
A third party tool such as ExifTool would be required to add in the missing “extra” metadata that is lost via the export command… so probably much easier to simply use save as instead (unless this retained some other unwanted metadata).
i know for my work, i sell png files. to ppl that print the image on things. for them if they open a 72 dpi that's jacked up 3 x the orginal size bc of export, they are having to resize everything, clients dont want that. i cant use the save as feature bc like today, i made an image of a man, but 2 variants of shirt and 2 variants of skin tone, 3 variants of hair, all which were layers i grouped and combined over and over so i could then use burn tool in photoshop and add more hand painted brush look than ai can give me. then i want to export them, but now im going to spend more time putting them in their own docs to save as, bc this issue still doesnt have the option of 300 dpi.
If you are going to sell PNG file the your customers are going to print large you need to create the png files with a large number of high quality pixels so they will be able to do that. They will not be able to print a small image with a small number of pixels well. Interpolating a small image up in size does not work well you lose to much image quality. And if you do not interpolate a small image and set its print resolution to be high resolution is will print to small to be of use. Its all about having a good number of quality pixels to print with. You need to create large print size images. If you at a low print resolution the print maye be a good size but not have an acceptable image quality.
in Photoshop CS6 when using “save as” to PNG, the resolution metadata info is written to the PNG file as per the PNG standard definition. This info may display as 72 ppi in some programs (which is a historical value now used arbitrarily as an “accepted default value”, just as 300 ppi could be considered the same):
[PNG-pHYs] PixelsPerUnitX : 2835
[PNG-pHYs] PixelsPerUnitY : 2835
[PNG-pHYs] PixelUnits : meters
(28.35 cm x 2.54 cm = 72.009 inches, rounded down to 72)
However with Photoshop CC15, using a save as results in new XMP-tiff tags being added to the PNG file, which now show up as a resolution in Adobe Bridge (even in CS6). So for a file that was 473 ppi:
[PNG-pHYs] PixelsPerUnitX : 18622
[PNG-pHYs] PixelsPerUnitY : 18622
[PNG-pHYs] PixelUnits : meters
[XMP-tiff] XResolution : 473
[XMP-tiff] YResolution : 473
[XMP-tiff] ResolutionUnit : inches
(186.22cm x 2.54cm = 472.9988 inches, rounded up to 473)
It appears that in CC2018, Photoshop is now only using the correct PNG specification tags when using the “save as” command, as it did back in CS6!
So if one wishes to add this “non standard” metadata back in so that say Adobe Bridge can show a PPI value, the following ExifTool command could be used for a 300 ppi value:
exiftool -XMP-tiff:XResolution=300 -XMP-tiff:YResolution=300 -XMP-tiff:ResolutionUnit=inches -ext .png -r 'path to file or top level folder'
It appears that Photoshop automatically translates the 11811 pixels per metre value to 300 ppi when opening a PNG file that contains the PNG-pHYs metadata into Photoshop (as a standard PNG file does not contain PPI based metadata).
Therefore there are two options if using ExifTool to change the metadata value of a file that has been exported and lacks this info:
1) Change the standard PNG-pHYs to a value that equates to 300 ppi when opened in Photoshop:
exiftool -PNG-pHYs:PixelsPerUnitX=11811 -PNG-pHYs:PixelsPerUnitX=11811 -PNG-pHYs:PixelUnits=meters -ext .png -r 'path to file or top level folder'
2) Add the non-standard TIFF resolution info, in addition to the matching PNG standard value (which may not be a great idea, Adobe have now stopped doing this, perhaps the PNG files were creating problems for other software).
Another option would be to make layer comps, then export layer comps to PNG files, however a custom script would be required to use the standard “save as” command, as the default Adobe script uses export/save for web which strips the PNG-pHYs metadata.