Due to the fact that almost every one of us now has, if not a phone, then a digital camera or tablet that has a more or less decent camera, now capturing any moment of life for a home collection is not a problem. At the same time, adjusting the parameters of images on gadgets, many are wondering how to convert pixels to centimeters. If you set the resolution too high, there will be little space for photos, 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 to Centimeters: What do you need to know to translate?
First you need to clearly understand what a pixel is. In fact, this is the smallest bitmap element . In other words, this is a miniature dot painted in one color or another. 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 to centimeters, it remains to deal with another important parameter called DPI. It is nothing but the density of dots per inch. The larger it is, the more sharp and high-quality the resulting image will be. Let it not bother you that instead of the usual centimeters you will have to use inches for calculations - it’s easy to convert inch to cm, 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 is simply not able to see more than 306 points in one inch.
Formula and Practice
After we figured out all the necessary parameters for the translation, you can easily derive a formula in order to quickly convert pixels to centimeters. The initial data of the fingerprint 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 size of the image in inches, and then multiply these values by 2.54 and translate the pixels into centimeters. As you can see, this translation is very simple. The corresponding formula can be written in the following form:
x = 2.54 * p / dpi, where:
x is the side length of the photo in centimeters,
p - side size in pixels,
dpi - print resolution density.
How to find out the screen pixel size
Sometimes for practical purposes it can be useful to know how many colored dots are contained in the centimeter of the device used. The easiest way, of course, is to find this feature in the instructions. But what if it is thrown out for a long time or this parameter is not specified there? In this case, you can simply open the image, the length and width of which in pixels are known in advance, and measure the same parameters with a ruler. After that, it remains to find the relations of the parties and get the desired result.
A bit of practice
Suppose we want to print a photo of nature in A3 format (two landscape sheets) in order to hang it on a wall. What minimum characteristics should such an image have? The standard dimensions of the A3 format are 297 × 420 mm (29.7 x 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 at least p = 42 * 300 / 2.54 = 12,600 / 2.54 ≈ 4,961 px, and the length: p = 29,7 * 300 / 2,54 ≈ 3,508 px.