About the App
truvis is an iOS app that embeds and detects invisible digital watermarks in images. You can insert up to 8 ASCII characters as a watermark into any image and detect it later.
How to Use
Embedding a Watermark
- Open the "Encode" tab
- Tap "Select image to watermark" and choose an image
- Enter watermark text (up to 8 ASCII characters)
- Tap the "Encode" button
- After processing, tap "Save to Photos" to save the result
Detecting a Watermark
- Open the "Decode" tab
- Tap "Select image to decode" and choose an image
- Tap the "Decode" button
- If a watermark is found, the embedded text will be displayed
FAQ
What characters are supported?
Up to 8 of the following ASCII characters are supported.
- Letters: A–Z, a–z
- Digits: 0–9
- Symbols: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
Japanese and full-width characters are not supported.
Does watermarking reduce image quality?
The watermark is designed to be invisible to the human eye. The impact on image quality is minimal, though slight changes may occur depending on the image.
What image formats are supported?
JPEG and PNG images from your photo library are supported. Very small images or unusual formats may not be supported.
How do I remove ads?
Tap the "Remove Ads" button below the ad banner to make an in-app purchase. Once purchased, ads will be hidden for the same Apple ID without repurchasing.
How do I restore my purchase?
If you reinstall the app, your "Remove Ads" purchase will be automatically restored as long as you are signed in with the same Apple ID.
Encoding or decoding fails
Please try the following:
- Restart the app
- Try a different image
- Make sure the image is not extremely small
- Update the app to the latest version
If the issue persists, please contact us.
Contact Us
For questions, feedback, or bug reports, please reach out via email.
Send an Emailtruvis_support@texpress.co.jp