Modern smartphones take great photos, but sometimes a particular frame turns out to be too small or blurry when viewed on a large screen. You want to print a photo in A4 format or use it as wallpaper on a 4K monitor, but the resolution of the original file is not enough.
Fortunately, the era when enlarging a picture was guaranteed to result in the appearance of terrible “squares” and soap is over. Today artificial intelligence algorithms you can restore details even from miniature images directly on your device. In this article we will look at which applications really work, how they are structured from the inside and how to achieve maximum results.
Do not confuse the usual stretching of pictures in the gallery and professional upscaling (upscaling). If you simply resize it in the standard editor, the phone will add empty pixels, making the image cloudy. We will use technologies that “find out” the missing details, restoring textures and clarity of edges.
Why regular stretching kills quality
To understand how to enlarge a photo correctly, you must first understand the physical limitations of a digital image. Each photo is made up of a grid of pixels. When you enlarge an image using standard gallery tools, the system uses the bilinear interpolationmethod. It simply takes neighboring pixels and averages their colors to fill in the new empty spaces.
The result of this approach is a loss of sharpness. The boundaries of objects become blurred, and small details disappear into a mess of colors. This is especially noticeable in texts, lines of buildings or hair in portraits. For high-quality enlargement, it is necessary to use more complex mathematical models.
⚠️ Attention: Increasing photo resolution by 4-8 times requires significant computing power. On older smartphone models (released before 2019), the process of processing one photo can take several minutes and greatly heat up the device body. Modern methods, such as neural network upscaling, analyze the contents of the frame. They don't just stretch pixels, but try to reconstruct high-frequency details that would be there if the photo was taken with a camera with a higher resolution.
Modern methods such as LANCZOS or neural network upscaling, analyze the contents of the frame. They don't just stretch pixels, they try to reconstruct high-frequency details that would be there if the photo was taken with a higher-resolution camera.
Before mass processing, do a test enlargement of one photo at maximum quality to check whether you are satisfied with the way a particular application algorithm works.
Top applications for upscaling on Android
There are dozens of utilities in the Google Play store that promise miracles, but only a few use real neural networks. We have selected the most effective tools that allow you to enlarge photos without losing quality on your Android phone, based on their work algorithms.
The application is considered the leader in this niche. Remini. It specializes in restoring old and blurry photos, focusing on people's faces. The algorithm completely redraws facial features, which gives stunning results in portraits, but may look unnatural in landscapes or objects.
It is great for more universal tasks. SuperImage. It is an open source application that uses SRGAN (Super-Resolution Generative Adversarial Networks) models. It works locally on the device, without sending your data to the server, which is critical for privacy.
- 📸 Remini —the best choice for restoring portraits and faces, works via the cloud.
- 🛡️ SuperImage —completely offline processing, support for various AI models, open source.
- 🎨 Pixelup —universal combine with coloring and enlargement functions resolutions.
- 🚀 AI Image Enlarger —specializes in enlarging images up to 400% while preserving outlines.
It is important to note that most powerful applications operate on a Freemium model. Basic features are available for free, but high-resolution or watermark-free processing often requires a subscription. Free versions usually limit the number of photos per day or processing speed.
Step-by-step guide: enlargement through neural networks
Let's look at the enlargement process using an example application SuperImage, since it gives the user the greatest control over the parameters and does not require a constant Internet connection. The interface may differ in other apps, but the logic of actions remains similar.
First you need to load the required processing models. In the settings menu, find the section Models or Upload models. For photographs, models marked General or RealESRGANare best suited. They are optimized for natural shots, as opposed to models for anime or art.
After loading the model, return to the main screen and click the add image button. Select a photo from the gallery. Before starting the process, make sure that the magnification factor 2x or 4xis selected in the settings. An attempt to immediately enlarge a picture by 8 times often leads to the appearance of artifacts.
☑️ Preparing for photo processing
Press the “Start” or “Process” button. Depending on the power of your processor Snapdragon or MediaTekprocessing may take from 10 seconds to 2 minutes. At this time, do not minimize the application, as Android may kill the background process that is consuming a lot of resources.
When finished, compare the result with the original using the Before/After slider function. If you are satisfied with the result, save the image in PNGformat to avoid additional compression typical for the format JPEG.
⚠️ Attention: Application interfaces and menu names may change after developer updates. If you do not find the described button, look for a similar function in the “Tools” or “Enhance” section.
Comparison of image processing methods
Not all enlargement methods are equally useful for different types of content. What is perfect for a cartoon can ruin a realistic landscape. Understanding the differences will help you choose the right tool for a specific task.
Traditional algorithms, such as bicubic interpolation, work quickly and do not require powerful hardware, but provide low quality. Neural network methods take time, but create details “from scratch”, relying on a database of trained images.
| Processing method | Working speed | Detail quality | Best application |
|---|---|---|---|
| Bilinear interpolation | Instant | Low (soap) | Quick preview |
| Bicubic | Fast | Average | Graphics, screenshots |
| Neural networks (SRGAN) | Slow | High | Photos, portraits |
| ESRGAN (Real) | Very slow | Extreme | Recovery of old photos |
As can be seen from the table, for serious tasks only the last two should be used point. However, it is worth remembering that a neural network can “hallucinate”, adding details that did not exist in reality. For example, add non-existent eyelashes or change the texture of fabric.
What are compression artifacts?
Artifacts are visual distortions that occur when the image is strongly compressed (squares, colored spots). Neural networks can either remove them or strengthen them if the model is trained incorrectly.
Export settings and saving the result
Saving the file correctly is half the success. Many users make the mistake of saving the improved photo back to JPEG highly compressed format. This negates all efforts to restore details.
Always select a format PNG to save upscaling results. This format uses lossless compression (lossless), which ensures that all newly created pixels are preserved in their original form. The file will weigh more, but the quality is worth it.
Pay attention to the metadata. When saved, some applications erase information about the shooting date, camera model, and geolocation. If it is important for you to preserve the history of the image, check the export settings or use special utilities to restore EXIFdata after processing.
It is also worth considering the color space. Most Android screens work in space sRGB. If you plan to print photos, make sure that the application does not convert the colors into the profile Adobe RGB without your knowledge, otherwise the colors may appear dull when printed.
The PNG format is required to save the results of neural network enlargement, since JPEG will introduce new noise and lose small details immediately after saving.
Common problems and ways to solve them
During the process, you may encounter that the application crashes with an error or displays a black screen instead of the result. Most often this is due to a lack of RAM RAM. Neural network models require loading large amounts of data into memory for calculations.
To avoid crashes, close all background applications before launching a heavy editor. Clear the system cache through your phone settings. If the problem persists, try reducing the zoom factor from 4x to 2x - this will reduce the CPU load by four times.
Another common problem is a “plastic” face. This happens when the algorithm smoothes the skin too aggressively, removing natural pores and wrinkles. In such cases, you should switch to the model marked Conservative or reduce the strength of the effect in the settings using the slider.
⚠️ Attention: If the application requires constant access to the Internet for offline functions to work, this may be a sign of hidden data transfer. Check permissions in Android settings before installing questionable software.
Sometimes after zooming in, colored halos appear around contrasting objects in the image. This is a sign of an overtrained model. Try changing the algorithm inside the application or reducing the sharpness of the final image in a standard editor by 5-10%.
FAQ: Questions and answers
Is it possible to enlarge a photo 10 times without losing quality?
Technically, you can enlarge it, but the quality will suffer. With a multiplicity of 10x, the neural network is forced to “think out” 99% of the information in the frame. The result often looks like digital painting rather than photography. The optimal limit is 4x.
Will the photo be clear when printed on a large format?
Yes, if the source was at least slightly readable. Upscaling increases DPI (dots per inch), which is critical for printing. However, when viewed point-blank from a distance of 20 cm, generation artifacts may be visible.
Does this increase the file size in the phone's memory?
Yes, the file size increases in proportion to the number of pixels and the selected format. An increase of 4 times in linear dimensions gives an increase in area by 16 times. A photo weighing 2 MB can turn into a file weighing 20-30 MB in PNG format.
Does this work with text in images?
Special models work with text, for example, DocSuperResolution. Conventional photorealistic models can distort letters, making them unreadable. For document scans, use specialized applications for OCR and document enhancement.
Do you need the Internet for all applications to work?
No. Applications like SuperImage or options with local models work completely offline. However, services such as Remini use cloud servers for processing, so they do not function without a network.