Pixels in centimeters? Elementary ...

Due to the fact that almost every one of us now has, if not a phone, a digital camera or a tablet having a more or less decent camera, now to capture any moment of life for a home collection is not a problem. At the same time, setting the parameters of pictures on gadgets, many are wondering how to convert pixels into centimeters. If you set the resolution to be too high, you will get little room for the photo, and sending them over the network can be long and problematic due to the large size. On the other hand, low resolution almost always means poor quality.

Pixels per centimeter: what do I need to know for translation?

First you need to clearly understand what a pixel is. In fact, this is the smallest element of the bitmap image. In other words, this is a miniature dot, painted in a particular color. It should be noted that the dimensions of one pixel are not static and depend on the technical characteristics of the device. In order to understand how to convert pixels into centimeters, it remains to understand one more important parameter called DPI. It is nothing more than a density of dots per inch. The more it is, the sharper and better the image will be. Let it not bother you that instead of the usual centimeters for calculations you will have to use inches - the translation of inch in cm is easy, you just need to remember the ratio: 1 inch = 25.4 mm or 2.54 cm. It remains to add that in printing, as a rule, Use dpi = 300, since it is commonly believed that the human eye more than 306 points in one inch is simply not able to see.

Formula and practice

After we have figured out all the necessary parameters for the translation, we can easily derive the formula in order to quickly convert the pixels into centimeters. The original print data can be found in the file properties or camera settings. The algorithm is as follows: First, we divide the length of the sides in pixels by dpi and find out the dimensions of the image in inches, and then multiply these values by 2.54 and convert the pixels into centimeters. As you can see, this translation is very simple. The corresponding formula can be written in this form:

X = 2.54 * p / dpi, where:

X - the length of the side of the photo in cm,

P is the side dimension in pixels,

Dpi - print resolution density.

How to find the pixel size of the screen

Sometimes, for practical purposes, it is useful to know how many color points are contained in the centimeter of the device used. The easiest way, of course, is to find this characteristic in the instructions. But what if it was long ago thrown out or is this parameter missing? In this case, you can simply open an image whose length and width in pixels are known in advance, and measure the same parameters with a ruler. After that, it remains to find the relationship of the parties and get the desired result.

Some practice

Suppose we want to print photos of nature in A3 format (two album sheets) in order to hang it on the wall. What are the minimum characteristics of such an image? The standard sizes of the A3 format are 297 × 420 mm (29.7 × 42 cm). For calculations, we use the standard value of 300 dpi. According to the above formula: p = x * dpi / 2,54. Then the width of the photo should be not less than p = 42 * 300 / 2,54 = 12 600 / 2,54 ≈ 4 961 px, and length: p = 29,7 * 300 / 2,54 ≈ 3 508 px.