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Photoshop has "pixel aspect correction", for which Google lists what appears to be thousands of answers on how to turn it off. I don't want to turn it off, but I want to apply it so that it's off but the image is now the aspect ratio that it was appearing to be with it on.

Simply put, I have an image which has the D1/DV PAL Widescreen pixel aspect ratio, 1:1.46. each such image is 256x155 px (WxH).

I need to make the image as shown in Photoshop with Pixel Aspect Ratio correction to be the actual way the image is.

I thought "apply" was the right way to say this, but all I see on Google and here is "how to turn it off". But I cannot think of a clearer way to explain what I want Photoshop to do. I want to apply the Pixel Aspect Ratio correction. Make it become "real".

I want things to be such that everything looks the same on the screen but the Pixel Aspect Ratio Correction is now off, and the image has been resized to show, at the same zoom, the way it did when it had Pixel Aspect Ratio Correction on. And I don't want to do the maths myself.

(I apologise for any frustrated tone this may carry. If it does, it is because I am really frustrated at this point. I've torn out so much hair I have a mohawk, now. This seems like something that should be simple to do.)

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  • All I can think is to paste to a new square pixel document then use Transform; but I've nothing I can test this theory on.
    – Tetsujin
    Nov 17 at 7:32
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To export with a different aspect ratio, you have to use square pixels and manually resize the image (non-proportionally) via Image > Image Size.

The Pixel Aspect Ratio Correction in Photoshop is merely an on-screen preview and it's not possible to "bake in" the preview. While the ratio is saved for a .psd file, it's never applied upon export because it's assumed the device rendering the image will use the aspect ratio. If you need an image actually at desired dimensions for a specific ratio, you need the image dimensions to actually match the ratio dimensions while using square pixels.

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Don't use that feature. That's not what it is designed for. It's only a preview for showing what an image will look like on a device that doesn't have square pixels.

Try this* instead:

  1. Do Image > Image Size

  2. In the dialog that opens up, disable the Aspect Ratio Lock (the link icon). Make sure the Resample option is checked, choose a method such as Preserve Details 2.0 or one of the other Bicubic options.

  3. Note the height shown for your image in pixels, and type the same value into the width field, followed by *1.46

For example

enter image description here

  1. If an image size error message shows, just ignore it and click OK to cancel the error, then hit OK button in the Image Size dialog to rescale the image

That's it, your image is now distorted to the required aspect ratio.

*Note: This will distort your image making it look squished/stretched, so if you don't want to do that then do the following instead to crop the image to a different aspect ratio without distortion.

  1. Select the crop tool
  2. In the tool options along the top, select Ratio, and in the following two fields type the aspect ratio you want. For example this is for a 4:3 aspect ratio

enter image description here

  1. Click and drag the crop tool to make a crop to that aspect ratio

  2. Hit the enter key to apply the crop

There are other ways to change the aspect ratio of an image, such as by using Content Aware Scaling, but success would very much depend on the suitability of the image. It doesn't work with everything, but it can be used to squish or stretch an image without distorting the subject. I'm not going to go into details here, but there's an explanation of the feature here on the Adobe help site

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    The way I understood the OP's request, it seems to me that they have an image that already looks distorted on a display with square pixels without pixel aspect ratio correction, since it comes from a source using non-square pixels, and they want to rescale it so that it looks correct on a square pixel display after export. While your (first set of) steps should indeed work for this, your commentary suggests that you've interpreted the OP's question rather differently (e.g. that they have an image with square pixels and they want to change its picture aspect ratio). Nov 17 at 14:14
  • @IlmariKaronen - you may be right. I feel the wording is a bit ambiguous to be honest and did consider that. If you are correct, then it could just be adjusted manual by visually transforming the image to squish or stretch it as required, until it looks right - or if you know the original aspect ratio, the original width and height pixel values could be typed into the Image Size dialog.
    – Billy Kerr
    Nov 17 at 19:25
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    This is still the answer. It is just a matter of knowing which direction one needs to stretch the image. DV PAL is 720 x 576 which is displayed as 1024 x 576, so to "bake it in," the image needs to be stretched in the horizontal direction. My confusion is mainly with the OP's statements: the DV PAL Widescreen "pixel format" is 720 x 576 with a "stretch factor" of 1.4222. So the numbers they quote are off.
    – Yorik
    Nov 17 at 21:44
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As the other answers note, you will need to manually resize the image non-proportionally. The details will depend on exactly what you're trying to do.

Unfortunately your question doesn't seem entirely clear on this — I suspect it's a terminology issue — but what I assume is that you have a 256 × 155 pixel image intended for viewing on a widescreen PAL television display with non-square (1.46:1*) pixels, and you want to scale it so that, after scaling and exporting, it looks the same on a display with square pixels as the original was intended to look on the non-square-pixel display.

If so, the easiest solution is to scale the image width by a factor of 1.46. To do this:

  1. Turn off pixel aspect ratio correction, if enabled. You say you already know how to do that, so I won't need to cover it (or spend time figuring out how to do it myself).

  2. Select Image > Image Size from the menu to open the image size dialog.

  3. Click the chain link icon next to the "Width" and "Height" boxes to turn off aspect ratio lock; now you should be able to change the width of the image without the height also changing.

  4. Set the image width to 146%. (That is, first change the width unit to "Percent" from the drop-down menu, and then enter "146" in the text box.)

  5. Optionally, choose your preferred resampling method, or leave it as the default. (You may want to experiment with this to see which method looks best for your images.) Then click "OK".

Your image should now be scaled from 256 pixels to 256 × 1.46 ≈ 374 pixels wide, and still be 155 pixels tall, and should hopefully look the same on your screen (with square pixels) as it did in the original video.

BTW, not that 374 × 155 pixels is a pretty tiny image by modern display standards, so you might want to scale it up at the same time. While you can do this in two steps, you'll probably get better results by doing the aspect ratio correction and upscaling at the same time. So, for example, instead of scaling the image width by 164% and height by 100%, you could scale the width by 2 × 164% = 328% and height by 200%.


*) You wrote "1:1.46" in your question, but all the sources I've checked say that PAL pixels are wider than they're tall, so it presumably should be 1.46:1. If the pixel aspect ratio for your image actually is 1:1.46, you should scale the image height up by 146% instead.


Ps. While trying to make sure I had the scaling ratio the right way around, I fell into a fairly deep rabbit hole of multiple contradictory sources on what the actual PAL Widescreen pixel aspect ratio is. Some say it's 1.46, some say it's 1.42, and some, like Wikipedia, list both.

Apparently the inconsistency (mostly) comes down to the fact that old analog TV formats have both horizontal and vertical overscan, meaning that the image area normally visible on the screen is smaller, and possibly a different shape, than the full transmitted image — and digital video formats based on the old analog standards inherited this whole complicated mess. So you end up with different screen aspect ratios depending on whether you count the overscan area or not, and while one would think that this shouldn't affect the pixel aspect ratios (which, after all, are supposed to just determine the pixel shape needed to make a circle on the screen look round and not oval), apparently it sometimes does, perhaps due to mistakes in standards or by people interpreting them.

What also particularly confuses me is that, as far as I can tell, the claimed pixel dimensions of your images (256 × 155 px) don't match up with any of the standard PAL video formats, which typically have storage aspect ratios (i.e. width / height in pixels) between 1.22 and 1.25.

Your images, meanwhile, apparently have a storage aspect ratio of 256 / 155 ≈ 1.65, which is actually fairly close to a typical widescreen display aspect ratio of 16:9 ≈ 1.78 or 16:10 = 1.6, assuming that the pixels are square. So perhaps my original assumption is wrong, and you do in fact have a picture with square pixels, and are trying to convert it to a video format with non-square pixels.

Anyway, whatever the case, the general solution is still always the same: use the image size dialog and remember to turn off the aspect ratio lock. Then you'll just need to figure out either the correct scaling ratio (and use "percent" mode) or the actual target pixel size that you want, and scale your image to that. And check that it looks correct afterwards.

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  • I'm grabbing frames from video files using ffmpeg, setting the width to 256 and the height to -1 (which means "whatever it takes to preserve the aspect ratio"), but older PAL and NTSC files have non-square pixels coming out. So these are coming from Handbrake DVD rips, ultimately, and doing whatever it did whenever it did it. It's for Tensorflow training. My thought was if I could "solidify" what PAC did and save it out, I could then use the resulting size for scaling everything else with Imagemagick Mogrify.
    – Dodger
    Nov 29 at 4:35

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