Screenshot DPI in Ps

[TenTin]

Why Ps doesn't care about screenshot DPI? I take a screenshot (with Snipping Tool in Windows 11), and when I create a new doc in Ps, it can recognize the size (from the clipboard) but forces 72 DPI. The default screenshot DPI on my Windows is 96. If I paste it into MS Paint, it cares about DPI and saves JPG, PNG and ... as 96 DPI. Is there a way to force Ps to read the clipboard screenshot's DPI?

 

[Conrad_C]

There might actually be no resolution metadata in the screen shot. What might be happening is:

MS Paint: If there is no resolution metadata, it probably assumes 96 ppi because that has been the Windows default for years.

Photoshop: If there is no resolution metadata, it is known to assume 72 ppi in many cases. This would be a wrong assumption in Windows, but like other Adobe applications that were first released on the Mac and later ported to Windows, Photoshop might still be assuming the 1990s-era Mac default of 72 ppi for images with no resolution metadata.

One way to test this:

1. Create a Photoshop document, and in Image Size, ensure the resolution is not 72 ppi, like set it to 96 or 300 or (what I do) a weird resolution like 273 that helps indicate whether the value is in the file and not assumed by the application.

2. Export that image using a command that is known to not include ppi metadata, such as File > Export > Export As.

3. Bring that exported image back into Photoshop, and choose Image > Image Size.

4. My guess is it will say 72 ppi. If it does, that means Photoshop assumes 72 ppi when no resolution metadata is included in the file.

Also, the bottom line for all of this: It may not matter one bit! Because if you look at both of your screen shots, the number of captured pixels is the same: 766 x 516 px. Especially for older 1x displays, ppi resolution is not an important part of screen shots, the pixel width and height is what’s important, and you have those, and they are the same in both applications.

PPI resolution does matter for HiDPI (Windows) and Retina (Mac) displays, because they use a pixel density scale factor. The system does need to know, for example, that 1532 x 1032 px on a 2x pixel density HiDPI display should be the same physical size as 766 x 516 px on a 1x display. But that is not a factor here.

[Trevor.Dennis]

That's an interesting take on it Conrad.  It has always annoyed me that images pasted into an Outllook post or Word document are so much bigger than they should be.

[TenTin]

Sorry! But you are absolutely wrong!

1. I take a screenshot and save it on my desktop.
2. Open a new doc in Ps (same size as my screenshot=WxH) with 72 DPI. Drag the screenshot into this doc ("resize the image when import" is disabled in prefs). The image size is smaller than the original one!

But! If I open a new doc (in Ps) with the same size (screenshot size HxW) with 96 DPI. Then drag it into this doc, the image size is the original size, not bigger or smaller.

All my graphic apps like Figma, Lunacy, Paint, FSCapture (editor) and Snipping Tool Editor can determine the resolution of the clipboard (96). Except Photoshop! Why Ps has to be such an idiot?!! It's a Godzilla vs others!

You can set the screenshot default DPI in Windows. By default, it takes the 96 DPI, and I didn't change it.

[D Fosse]

You misunderstand. There is no such thing as ppi on screen, and there is no such thing as "size". It's just pixels. A screenshot is just so many pixels wide by so many pixels high.

You can paste this into a new document, which may have a ppi value, and then it gets a size. Size is always a function of whatever ppi number is assigned. This is arbitrary. You can assign whatever you want, and the size varies accordingly. But the pixels remain the same.

Ppi is not a property of the data. It's just metadata, an instruction.

Different applications assign different ppi values as default when there is no ppi number already. Photoshop happens to assign 72 by default. Microsoft applications happen to assign 96 by default.

Again: there is no "size" until you assign a ppi number. The ppi number is a way to translate from pixels to physical size.

[TenTin]

There's something obvious! The Windows clipboard DPI is 96. Why Ps can't get it, but the other apps can get/read it?!

I said you can set custom DPI for screenshots in Windows to tell the app (through the clipboard) what DPI they have to grab from!

I'm not a Windows expert, but I know they have considered everything (unlike Apple, which is just focused on the UI).

[Lumigraphics]

Its not DPI, its PPI. And PPI is irrelevant in Photoshop. Photoshop measures things in pixels. PPI is DERIVED data, not absolute data. You can set your screenshot to 1,000,000 PPI and it will work just the same.

[TenTin]

PPI = Pixel per Inch (Screen)

DPI= Dot per Inch (Print)

MS Paint works with/on screen! Photoshop works with/on screen!

🤧

[D Fosse]

The Windows clipboard DPI is 96.

By @TenTin

No, the Windows clipboard is not 96 ppi.

When you make a screenshot, the number of pixels w x h is copied to the clipboard. Ppi does not come into it.

Again, the ppi number appears when the screenshot is reopened in another application. Most applications need to assign some ppi number for other unrelated reasons. But any number will do. 72 or 96 is just arbitrary.

And pixels per inch applies on image level. Dots per inch applies to print; ink dots on paper.

On screen there is no ppi. There is just so many pixels wide by so many pixels high. You can always calculate how many ppi that constitutes, by dividing pixels by screen size, but that has nothing to do with the data or any screenshots taken.

You still misunderstand this on a fundamental level.

[Kevin Stohlmeyer]

@TenTin go to Photoshop Preferences/Units and Rulers - what is your Screen Resolution set to?

[TenTin]

Correct answer?!!! 😴

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💤

 

[D Fosse]

Again: this does not affect a screenshot.

This setting is for letting Photoshop calculate a resampled screen size for the whole image that matches the print size, as given by the ppi number assigned to the file.

[TenTin]

I set the Screen Res to 96 (in Ps prefs), took a screenshot (saved on the desktop automatically), and brought it into a new doc (Ps). The size is smaller than the original size!!!
God, god, god, god... You moron Photoshop...

I'm not OppenBomber to solve such garbage atomic formulas. Just give up such rubbish maths. Can anybody tell me how I take a screenshot (Windows default PNG 96 DPI) and then drag it into a Ps doc (72 DPI) without scaling?

[Lumigraphics]

You have a complete, utter misunderstanding of how this all works. PHOTOSHOP WORKS IN PIXELS.

SImply open your screenshot, which will be x pixels by y pixels. You can assign a PPI value if you want once it is opened without changing the number of pixels.

[TenTin]

I know I can change the screenshot DPI to 72 and then drag it into a new doc with 72 DPI without scaling it!
Also, I can open a new doc with the same (screenshot) size and 96 DPI, then drag it into this doc without scaling.
There is one/two steps more I have to do.

[Lumigraphics]

:headdesk:

IGNORE the PPI setting!!!!!!!!!!

Create your document. 600 x 600 pixels, say.

Make your screenshot. Capture, let's say, 200x200 pixels. Paste it into the first document.

NOTHING WILL CHANGE! It will take up 200 x 200 pixels. Just that simple.

[D Fosse]

A screenshot doesn't have a ppi value. It just has pixels.

The ppi value that you see is a default number assigned by the application that opens it.

[Conrad_C]

OK, I got curious and ran some tests.

I have Windows 10 in a virtual machine. I set both Snip & Sketch and the older Snipping Tool (now deprecated by Microsoft) to save screen shots to files instead of to the clipboard, to remove the variable of how a pasting application might interpret PPI. I had each application save the screen shot as PNG.

On macOS, I did the same thing using the built-in screen capture tool, on both a 1x and Retina 2x display. In macOS, the command line process “screencapture” is what is used by the standard macOS capture shortcut (Command+Shift+5), and the screen capture commands in Apple Grab, Apple Preview, etc.

I transferred all of the images to the Mac, and inspected PPI in Photoshop, Affinity Photo 2, GraphicConverter, and Adobe Bridge*. All agreed on the numbers in the table below, indicating that some screen shots saved with the bundled OS screen capture tools (not through the clipboard) on both Windows and macOS do include embedded PPI metadata, except for screen shots taken on the Mac on a 1x scale factor display. (My virtual machine is not doing Windows HiDPI properly, so I couldn’t test that.)

Platform	Capture application	HiDPI/Retina	Embedded PPI reported by apps
Windows 10	Snip & Sketch	1x	96
Windows 10	Snipping Tool (deprecated)	1x	96
macOS	OS “screencapture” process	1x	(none, some applications like Photoshop assume 72)
macOS	OS “screencapture” process	2x Retina	144

What does this have to do with the original question?

I have always believed that the way to fix an entire class of problems like this, is to stop using the clipboard for screen shots. On both macOS and Windows, I set all screen shot utilities to save a file to a screen shots folder, not going through the clipboard. That way, every screen shot is a discrete file that can be referred to or reused later, it can have full file properties such as ppi, it avoids dealing with how applications might interpret clipboard data, and it also saves the multiple steps of app switching, pasting, and manually creating a document for every screen shot, because the document is already created!

*Adobe Bridge 14 seems to have a strange bug where its metadata panel reports 96 ppi as 95, and 144 ppi as 143…

[D Fosse]

I honestly think this is getting overcomplicated.

The screenshot has no ppi. Any ppi number is assigned by the application opening and processing the screenshot. That includes screenshot utilities. In that processing, they assign a ppi value.

All applications will assign a ppi number if there isn't one - they may need to print it, they may need to calculate font sizes, and so on.

Microsoft applications, including any screenshot utilities, assign 96 ppi. That doesn't mean the screenshots are 96 ppi. It's just a chosen number. Photoshop chooses a different number, 72. Any number will do, as long as there is one.

All of the above also applies to retina/4K screens. With these screens, applications/OS perform a linear 2x scaling before the image hits the screen. So the captured screenshot is already 4x the pixel count, and processed in the same way. But usually with an assigned 2x ppi value.

[Stephen Marsh]

@TenTin 

If you really, really want Photoshop to default to 96ppi you can use the following script to automatically create a new doc with the clipboard content and pixel width/height at 96ppi. A custom keyboard shortcut can be assigned to an installed script.

/*
New 96ppi Document from Clipboard Content.jsx
v1.0 - 22nd November 2023, Stephen Marsh
https://community.adobe.com/t5/photoshop-ecosystem-discussions/screenshot-dpi-in-ps/td-p/14247769
Based on:
https://community.adobe.com/t5/photoshop-ecosystem-ideas/feature-request-auto-paste-when-creating-clipboard-sized-file/idc-p/12984246
*/

#target photoshop

try {
    var origUnits = app.preferences.rulerUnits;
    app.preferences.rulerUnits = Units.PIXELS;
    // New Doc from Clipboard - Courtesy of the late Michael L. Hale
    var desc = new ActionDescriptor();
    var desc1 = new ActionDescriptor();
    desc1.putString(stringIDToTypeID("preset"), "Clipboard");
    desc.putObject(charIDToTypeID("Nw  "), charIDToTypeID("Dcmn"), desc1);
    executeAction(charIDToTypeID("Mk  "), desc, DialogModes.NO);
    activeDocument.paste();
    activeDocument.activeLayer = activeDocument.layers[activeDocument.layers.length - 1];
    activeDocument.activeLayer.remove();
    //activeDocument.flatten();
    activeDocument.resizeImage(null, null, 96, ResampleMethod.NONE);
    app.preferences.rulerUnits = origUnits;
} catch (error) {
    alert("The clipboard is empty or does not have suitable content to create a new document!");
}

 https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

[TenTin]

Sorry guys, you all are pixel experts (!) and I am your headache, but don't be angry with me! I am an old tortoise, calm and cold blood! You live in an ivory tower, and I live in a Humble hut!

@Conrad_C By this, it means I wasn't wrong! The Clipboard DPI/PPI in Windows is 96!

@Stephen Marsh Thanks for the Script. It's cool. I tried, and it was exactly the thing I meant! Unfortunately, it ISN'T a NATIVE feature, and I have to assign an EXTRA keyboard shortcut!!!

Conclusion: Ps is idiot enough to get not the clipboard PPI/DPI! And you proved the clipboard PPI/DPI is 96, and also proved My idiot Ps can be forced to do the right job (grab the clipboard 96 PPI/DPI) with just multiple lines of codes (Script). Top of the most, you proved having a big name does mean nothing! Even a kindergarten painting app (MS Paint) can conduct the Godzilla to the hell!

[Lumigraphics]

You still don't understand. Its well past time for this thread to be locked.

[TenTin]

Could be more polite, Sir!!!

[Stephen Marsh]

can be forced to do the right job (grab the clipboard 96 PPI/DPI) with just multiple lines of codes (Script).

By @TenTin

To be clear, the script isn't grabbing the PPI info, it is resizing the image without resampling to 96ppi as that is the known target.

I agree with @Conrad_C that it's often better to avoid the clipboard and to save screenshots directly to a file from the screenshot software.

[TenTin]

Thanks for the time. 👍🏻