How to make a document scan on Xiaomi Redmi 9C: the full guide

Modern smartphones have long ceased to be just a means of communication, turning into powerful pocket offices capable of replacing the scanner and printer in emergency situations. 9C, People often wonder if you can scan a passport, contract or certificate without installing third-party software. MIUI and a competent approach to photography.

The process of creating digital copies based on Android with the shell MIUI 12 or later does not require complex manipulations, but has its own nuances that must be considered to obtain a clear image. High-resolution matrix allows you to capture the smallest details of text, but automatic camera mode often distorts colors or leaves glare. Understanding the principles of the software will help avoid unnecessary errors.

In this article, we will take a closer look at all available methods of digitizing papers, from using the built-in Documents functionality to setting up a professional camera mode. You will learn how to properly prepare the workplace, customize the exposure and choose the optimal format for saving your files so that your files look professional on any screen.

Use of the built-in scanner in the Annex Documents

The easiest and fastest way to get a digital copy of paper is to use the native system toolkit, which is already preinstalled on your Redmi 9C. The MIUI shell has a special application called Documents (or Scanner depending on the firmware version), which automatically defines the boundaries of the sheet and aligns the perspective, which saves the user from having to manually crop the image.

To start the process, you need to find the appropriate application in the Tools folder or through a desktop search. Once you open, select Document or Text mode, hover the lens over the sheet and take a picture. The system automatically processes the edges, removes shadows and increases the contrast of text, turning the photo into a full scan.

However, it is worth considering that automatic processing algorithms do not always work perfectly in poor lighting or if the text is printed on colored paper. Digital correction can make the background too white and the letters blurred, so always check the result before saving. In some cases, it is better to use Photo mode and manual processing.

⚠️ Note: When using an automatic scanner, make sure that your fingers do not close the corners of the document, otherwise the system may misdetect the trimming boundaries.

The main advantage of the built-in solution is that it does not need to download additional applications, which saves precious space for the device’s internal memory, and integration with the file system allows you to instantly send scanned files to messengers or cloud storage.

Setup the camera for perfect digitization of text

If the built-in scanner doesn't meet the quality requirements, you can use the standard Camera app manually or with the right settings. The Xiaomi Redmi 9C has a 13MP main camera module that can capture even fine print if you have the right shooting conditions. The key here is focus and exposure.

Point the camera at the document and tap the screen in the text area to capture the focus. Next to the focus slider, there will be an exposure slider (sun) that needs to be lowered down a little, which will reduce the amount of light that hits the matrix, making the background whiter and the text more contrasting, removing the effect of illumination.

For best results, it is recommended to use the Pro mode if it is available in your version of the software, where you can manually set the ISO to a minimum value (usually 50 or 100) to avoid digital noise, and set the white balance according to the lighting.

💡

Use a timer for 3 or 5 seconds when shooting from your hands in Pro mode to exclude microsmosis from pressing the shutter release button.

Remember to wipe the camera lens before shooting, as greasy spots from your fingers can create a soapy image effect that cannot be fixed software.

Third-party applications for professional scanning

When built-in tools are not enough, specialized applications from the Google Play Market come to the rescue, which have advanced image processing algorithms, with the leaders in this niche being Adobe Scan, Microsoft Lens and CamScanner, each offering a unique set of features for working with documents.

These programs not only level perspective and remove glare, but also recognize text (OCR) by translating it into an editable format, which is especially useful for students and office workers who need to quickly extract information from paper, and installing this software turns your Redmi 9C into a powerful batch-enabled scanner.

Compare the main features of popular applications in the table below so you can choose the most suitable for your tasks:

It’s worth noting that many of these applications require an internet connection to run some features, such as cloud sync or advanced language recognition, and that when using free versions, ads or watermarks may be present on the final files.

Workplace and lighting preparation

The quality of the final scan depends 80% not on the megapixels of the camera, but on the conditions in which the shooting is performed. Even the most expensive smartphone will not be able to convey text properly if the room is dark or the light falls unevenly, creating deep shadows. For the Xiaomi Redmi 9C with its f/2.2 aperture, the correct lighting is critical.

The ideal option is diffuse daylight by the window, but without direct sunlight, which creates bright glare on glossy paper. If there is no natural light, use two lamps, positioning them on the sides of the document at an angle of 45 degrees, which will minimize the shadows from irregularities of paper or fingers.

The best background for a document is a dark, matte surface contrasting with a white sheet, which will help the pruning algorithms automatically and accurately determine the boundaries of the document, avoid colorful carpets or wooden tables with a pronounced texture, which can knock down automation.

⚠️ Note: Do not use flash when scanning documents, especially laminated or on glossy paper, as it will create a huge white spot in the center of the frame, overlapping the text.

Lock your phone in a still position, using a tripod or just pointing it against a stack of books. Trembling hands are the main enemy of clarity, especially in low light when the camera shutter speed is increased.

Processing and saving scanned files

Once the image is taken, there is a post-processing phase that allows you to bring the document to its perfect state. The Xiaomi Gallery has a basic editor that allows you to change the contrast, saturation and framing. However, it is better to use specialized filters such as Document or W/B to work with text.

When saving a file, it is important to choose the right format. JPG is great for sending via messengers or printing, as it provides good quality with a small file size. For official documents containing several pages, the PDF format is preferable, which combines all sheets into one file and prevents accidental editing.

Remember to give files clear names immediately after saving, such as “Passport Rollover_2023» instead «IMG_20231025_1230». This will save you a lot of time in the future when you need to find a specific document in a gallery of thousands of photos.

Frequent errors and ways to fix them

Even experienced users often make common mistakes that negate all digitization efforts. One of the most common problems is the barrel effect, or perspective distortion, where a document is shot at an angle rather than a top. While the software can align an image, strong perspective reduces readability at the edges.

Another mistake is shooting in low light without a tripod. The Redmi 9C camera in the dark automatically lengthens the shutter speed, and any micro-movement will lead to grease. If there is little light, it is better to increase the ISO (noise will be added, but the text will be clear) or add artificial lighting, than risk obtaining an unreadable file.

⚠️ Warning: Avoid shooting documents from the screen of another device (computer or tablet), as the image will appear characteristic stripes (moires), which will make the text unreadable for recognition systems.

Also, users often forget to check the edges of a document after automatic cropping. The algorithm can cut off important information, such as seals, signatures or dates located close to the edge of the sheet. Always take a frame with a small margin in the fields.

Compliance with these simple rules will allow you to get digital copies of documents on Xiaomi Redmi 9C quality comparable to the work of an office MFP. Technology has stepped far forward, and your smartphone is quite capable of replacing bulky appliances for household tasks.

💡

The main secret of a quality scan on the phone is not the application, but the correct lighting and the perpendicular position of the camera relative to the sheet.

FAQ: Frequently Asked Questions