What happens to a picture if you stretch it. (monitor,resolution,pixel question)

[Curious_B]

I’m not sure but I think a picture’s size is measured in resolution. A 50x50 picture will be bigger on a 28’ 1080p monitor than on a 24’ 1080p monitor
You can stretch and minimize it how you like though.
So what exactly happens to a picture if you make it bigger? Say you stretch this 50x50 to use the whole screen of the 1080p monitor? What exactly happened to the 50x50 pixels? They just appear huge? I mean your monitor still has its 1080 height by 1920 wide pixels so now instead of showing true 50x50 pixels more pixels are being used to fake the appearance of 50x50 normal pixels?

Does that also mean if you play a 480p video file on a 4K monitor that the pixels will look “huge” or its not that bad?

 

[gytisxp]

Two options for the display: either display the original resolution in the center of the screen and do black bars without it or stretch it to fit the display ( use like 40 pixels for every 1 pixel in the original )

24' 1080p and 28' 1080p images would be the same size. Its the pixels that would be larger / smaller

 

[jafrankl]

Stretching images increases the pixel size by a scale factor. A 10x10 image stretched to 100x100 would have each pixel size merely increased by a factor of 10. This makes images unclear/blurry and gives extreme poor quality. Changing the size of a monitor changes the pixel density (pixels/inch). Here's a good calculator/approximator for pixel density: http://dpi.lv/

 

[Curious_B]

>( use like 40 pixels for every 1 pixel in the original )
Isn't that going to make the picture/video ugly?

 

[Curious_B]

Stretching images increases the pixel size by a scale factor. A 10x10 image stretched to 100x100 would have each pixel size merely increased by a factor of 10. This makes images unclear/blurry and gives extreme poor quality. Changing the size of a monitor changes the pixel density (pixels/inch). Here's a good calculator/approximator for pixel density: http://dpi.lv/

So a 480p video is going to have a worse time fully stretched on a 4k monitor because of insane scale factor than on a 1080p monitor?

 

[jafrankl]

Yes. There are more pixels for the video to try to fill, so each pixel will be stretched even further. If you consider each resolution (1080p, 1440p, 4k) as a factor change of 10 or more, the 10x10 goes to 100x100, 1000x1000, and 10000x10000, respectively from my example. Not sure about the exact factors (each screen has a different number of exact pixels), but getting better quality video is the easiest solution, or watching in a smaller form.