I have many images I want to upgrade from 72 DPI to 300 DPI. Is it possible to somehow save them all at once, as well as change the resolution of the new, saved images?

Just like how photoshop can with Windows > Action
https://community.adobe.com/t5/photosho ... 946?page=1

Thanks!

There is no batch processing in krita so the answer is no.
I'm sure there are free applications that do this. I remember that Irfanview did it, if it's still available.

Imagemagick should be able to do this.

I didn't try ImageMagick, but Irfanview works! That's amazing! It has a lot of options to modify the images too.

Thank you so much for your responses, gents!

Also, I was wondering what is the resolution for an image to be considered "HD," as if it were a 1080p video equivalent? 1600x1600 at 300DPI?

stgemma wrote:Also, I was wondering what is the resolution for an image to be considered "HD," as if it were a 1080p video equivalent? 1600x1600 at 300DPI?

1080p = 1920x1080 pixels. That's fullHD. (There might be some other values instead of 1920 but very rarely and they are very similar). Usually for drawing you might want to get a bit higher, like 2500x3000 or something similar, depending on how powerful your computer is.

Note that I haven't mentioned DPI; that's because in digital painting DPI doesn't matter. It only matters when you want to print it. Then DPI will translate the digital units (pixels) to real-life units (cm, inches).

For example fullHD in 300 DPI (which is considered somewhat optimal for printing, but it depends what you want to print) is just 6.40 inches x 3.60 inches.
FullHD in 96 DPI = 20 inches x 11.25 inches. For the computer and you, looking at the screen, inches don't matter because your display will scale it down or up however you want, and what matters is the amount of information you can save in an image, which is the size in pixels.

Note something funny: 1920/300 = 6.4. Basically (in one dimension) [size in pixels] = [size in inches] * [dpi].

- If you have one specific picture with a specific pixel size, if you have higher DPI, the result of printing will be smaller, but it will look more detailed. You'll fit the same amount of pixels on smaller piece of paper.
- If you want to print to a specific size of paper like A4, which means the size in inches is constant, the higher DPI you choose, the more detailed the resulting image will be because you'll be able to put more details there because the size in pixels will be bigger as well. You'll fit more pixels on the same area on paper.
- If you have one specific DPI, like 300, the bigger the image is in inches, the bigger it will be in pixels and the other way around.