In the case of digital printing and image processing, one has to deal with various terms, the meaning of which is not understood correctly by everyone. Such terms include, for example, the words "pixel" and "resolution".
Instructions
Step 1
If you ask the question “how many pixels are in an A4 sheet”, it turns out that there is no definite answer to it. The fact is that, unlike centimeters and millimeters, a pixel does not have specific dimensions. Essentially, a pixel is the smallest two-dimensional logical object used in computer graphics. The combination of pixels of certain colors creates a particular image on a screen or sheet of paper. Depending on the type of device, a pixel can be square, rectangular, octagonal, or round. The word "pixel" or "pixel" itself is an abbreviation of the English phrase pix element, which means "image element".
Step 2
Pixel size is not a constant value, as it is directly related to such a concept as "resolution". Resolution in this case means the number of pixels or dots that fit into one or another unit of area or length. Typically, resolution is measured in dpi, which means dots per inch - the number of dots per inch. Naturally, the higher the resolution, the better the image on the screen or paper, and vice versa.
Step 3
Thus, the number of pixels in an A4 sheet directly depends on the resolution used in creating the image and printing. Most graphics programs produce images at 72 dpi by default, but 300 dpi is most commonly used for quality prints. Knowing the dimensions of A4 sheet (297x210 mm) or 11, 75x8, 25 inches, you can calculate the number of pixels at a given resolution. So, for a resolution of 72 dpi, the number of dots on an A4 sheet will be 502524, and for a resolution of 300 dpi - more than 8, 7 million pixels.
Step 4
In practice, it looks like this: for example, you have an image with a size of 1000x1000 pixels, when printing at 72 dpi it will take a sheet of paper 35 x 35 centimeters, and if you send it to print at 300 dpi, then the final size will be only 8.5 by 8.5 centimeters. Of course, a small image can be stretched over a whole sheet, but it will become tiled and grainy. And if you print a picture with a low resolution, the color rendition will suffer significantly. Therefore, in the printing industry, as a rule, large enough images are required, allowing them to be printed at high resolution, which ensures a good quality photo or illustration.
