Understanding resolution in digital image

Recently, there is a question about the useless of higher resolution. That is, photos printed with higher and lower resolutions cannot be distinguished.

It is the distinction of digital imaging. Yet, this is also the easy misconception about it too.

I have mentioned that years ago, when discussing with some specialists about inkjet printing in the true 720 dpi period, they insisted that A4 print required 24 megabytes. I had printed a photo A4 size with just 18 megabytes and many people including them and some famous photographers found it satisfactory.

At that time, I had found that there should not be any exact resolution for output. It all depended on the type of image.

The same truth is applied today. Of course, the major reason is the printing technology. I do not have time to search whether all digital photo printers are employing the same method. I mean that output may use vector technique. Reading the image file and converting the colors to vector format, then the printing can give a much better quality even if the original resolution is lower than what had been expected before.

Do not take this as something strange. This is the good thing for digital imaging and this is something that we need to master.