The use of some terms in digital imaging has become a matter of great confusion for many people. If you have ever wondered what is DPI of an image, it is a cumbersome task for a layman to differentiate between Dots per Inch (DPI) and Pixels per Image (PPI).
Well, both DPI and PPI are the measure of resolution for both on-screen and print images. It is pertinent to note that DPI is relatively an old term. People have been using this very term to relate everything about the digital images and their size and resolution before the appearance of PPI in recent years. Currently, PPI is most commonly used to manage the resolution and scale of digital photos, yet DPI is still used for some software and documents.
The following lines explain what Dots per Inch (DPI) means and how it affects the resolution of your image.
If you don’t know what is DPI in the image, you should know that the DPI refers explicitly to the printers. In some words, it is only used in printers nowadays. Everyone should be aware that all the printers consist of different colored inks that combine to create every single pixel output. There are usually 4-6 differently colored inks in a printer. The printer works on the principle of mixing all these colors to create an image.
The printer has to mix the inks because of a small number of colors available to it. It has to create an image using only these 4-6 colors. A series of tiny dots create each pixel of an image. You can consider these tiny dots as sub-pixels. It is important to note that the tonality of the printer will be higher if there are more dots per inch in an image, and this is what is DPI of image.
All the images follow the same old rule more DPI better quality, that is higher the DPI, the better will be the quality of the image. Moreover, the resolution of a digital image is incomplete if you do not request the size of the print along with it.
Colors in the image will also look better if the DPI is higher. Most importantly, the colors will blend naturally and smoothly. There is also a reverse side of using high DPI in image processing. That is the printing job will be slower, and the printer will use more ink. To overcome this problem, you must try to lower the DPI setting without distorting the DPI image. The lowest DPI setting, which does not reduce the DPI image quality is the one you should be using.
Against common perception, DPI meaning has nothing to do with the video quality. Almost all the modern video formats, as well as rasterized images, store their data solely as pixels. They do not depend upon DPI or real-world measurements such as inches for their quality. On the other hand, monitors also display video only in units of pixels. If you are displaying a video or rasterized image, the monitor maps them pixels by pixels instead of dots per inch.
You may have to use DPI in videos and rasterized images when you want to map real pixels into real-world measurements. For example, 20 points are roughly 0.28 inches. Therefore, a 20 point Font will use dots per image settings to determine how many pixels it should use.
Now, we will answer what is DPI resolution best for your image. You might be surprised to learn that most pros recommend using 300-400 DPI resolution for digital photos. This raises a fundamental question: what does higher DPI do. Why not use a higher 1000 or 2000 DPI for an image or for that matter, lower 120 DPI? Is there a threshold for lower and higher image resolution beyond which you should not venture. Professionals consider 300 PPI photos as a high resolution, but when printed, that’s why professionals recommend it and suitable for most of the users.
It is also pertinent to note that an image with 72 DPI might look amazing on your computer screen. However, you may be shocked to test the image on your 20 HDTV7. The low dpi vs. high dpi picture is a long time doubt too many people. Although 400 DPI is always better than 120 DPI, the actual DPI resolution you want to use depends upon the type of image and your requirements.
For instance, most old photo labs would develop your photos using only 300 DPI physically. 300-400 DPI is still good enough for most of the photos. For example, if you scan an old photo at 300 DPI, you are very likely to get an exact copy of your photo. On the contrary, if you scan it using 600, 900 or higher DPI, it will distort your photo instead to provide you with more details. 300 DPI is the limit for such photos, and you should not go higher or lower.
Again, the quality of the image depends upon the device on which you are viewing your image. You might distort your image if you want to get the bigger print of your 300 DPI photo. This is where you must scan your image at a higher DPI. It will help you retain the image quality without stretching the picture.
Yeah, we just told you that the higher the resolution better the quality of an image. But pictures with the same PPI can also have different variety of an image. You can follow some of the tips listed below to improve the quality of the image:
You must be thinking does DPI affect file size? Long answer short, the DPI can also change the physical size of the image. You might have to increase or decrease the DPI to set the image to the default size of the printer you are using to print the image. For example, the DPI of the photo should be 400 if the default print dimension is 5 inch and you want to set the image width to 2000 pixels. The formula is simple. You will divide 2000 with 5 to get 400 DPI.
You should try not to resample or resize your image while changing its DPI. It is advisable to retain the original pixel dimensions while changing your DPI. These pixels usually determine the real digital resolution of an image. Image quality DPI means you will be able to retain the size and resolution of the original image without distorting its quality. The only thing you will be changing is its inner dots per inch (DPI) dimensions.
There are many programs such as Photoshop and Illustrator, which help you change the DPI without disturbing the physical size of the image. The only thing you need to keep in mind is that you should never resample or resize your image while changing the DPI. Your new photo will be a carbon copy of the original as long as its pixels remain unchanged.
It is essential to set the correct DPI of an image; otherwise, you might end up having some glossy, blurry, or low-quality photos. So, you must know how to change the DPI of an image. You can easily change the DPI of an image using photoshop. Open your photo in photoshop and go to image, and then Image size. Make sure to uncheck the resample image button as it will further deplete the quality of your image.
To increase dpi of image type your required resolution and set it as Pixels per inch. The width and height of the image will change automatically based on your preferred choice. You can also adjust the height or width of the image, and DPI will adapt accordingly.
The words Dots Per Inch (DPI) and Pixels Per Inch (PPI) are generally accepted mutually to explain the resolution of an image. Still, the terms do not imply the same characteristic and there are clear distinctions between the two:
First, even though PPI applies to the resolution of an on-screen picture, it can also influence the character of the ultimate printed image. Next, even some expert calls that images must be at a specific DPI level before they can be published.
In other words, this means PPI, not DPI. The term DPI is a process to resolve the size of a picture on paper. For printing applications that apply DPI to fix the print size, improving the DPI will make the printed size smaller, while reducing the DPI makes it larger.
PPI describes the nature of a digital image presented on-screen. But, it also adds to the characteristic of an image. If a digital image includes too few pixels, the image will not have very much particular and develop pixelated. Digital pictures with more pixels have a more satisfying aspect. The volume of PPI is defined by the picture size.
The usual practice is that you should go for 300 dpi. This is a high feature for images, and it’s uncertain how many additional features the human eye can even notice beyond that level. But if the picture is too inadequate to calligraph at 300 dpi, don’t think much. The expected viewing range of the copy represents a substantial part of what resolution you require.
For example, take a 1px line on the most suitable resolution screen. Now implement a pixel number 130% more petite. To choose the screen the CPU will have to create the visuals at 150%, adding all the things by 1.3. 1*1.3=1.3, but the problem here is that you can’t have mixed pixels.
This is where you can use a Retina Macbook Pro to change the resolution of the image. It will reveal the window and allow you to use the resolution 1280*800px. It manages the user’s resolution practice to display a size proportion.
The nature of the video users are playing will influence how it appears on the display screen. For example, a high-resolution display screen won’t improve the resolution of the video user is watching. If you want the extremely desirable feature, look for a copy make sure to go for the display in high-definition — 720p or 1080p.
Some screens or devices aren’t proficient in delivering high-quality video content. Even if the resolution of the screen is1080p and the video feature is particularly distinguished, the device operating the content is important.
The DPI range of a printer usually demands to be more powerful than the pixels per inch (PPI) measure of a video or image performance to give the equivalent-quality result. This is owing to the insufficient variety of colors for each dot normally possible on a printer.
At each dot point, the most uncomplicated type of color printer can either issue no dot is of a solidified volume of ink in four color channels known as cyan, magenta, yellow and black ink.
For example, if the pixels of a picture does not alter, then it has the identical digital interpretation no matter what quantity is set in the DPI/PPI setting. One portion in the state of printing is multiple pixels per inch are passed to the printer.
If a user is using an older photo editor software to configure the DPI to set the size of the output image then he/she has to change the DPI to accommodate the size of the printed image.
Most newer photo editor software just allows users to configure a size 5″ x 7″ for the picture. Programs that operate DPI to settle the area of published output are applying PPI.
A high-resolution picture contains high-quality pixels, stored in a file format or a high-quality JPEG format. This can provide the aspired PPI which is normally 300 for the proposed print size.
To conclude, we would recommend your images to have a resolution of 300 dpi or higher if you want a high-quality printed copy. We often see that a web image printed becomes blurry, and due to lest PPI, the images get distorted a lot. Images for newspapers can usually be around 200 dpi due to the low quality of the paper. And if you want a web image you can use 72 dpi image size as images with higher DPI will be reduced to display at 96 dpi or less.
While creating an image, resolution, and quality is often neglected, but it is essential for any photo when you are putting so much effort and time. So, we hope you are clear with the DPI meaning and make sure to choose the right resolution for your image next time you want to click a perfect candid.
About the Author
ByteScout Team of Writers
ByteScout has a team of professional writers specialized in different technical topics. We select the best writers to cover interesting and trending topics for our readers. We love developers and we hope our articles help you learn about programming and programmers.