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Overview

Display Monitoring is an application that periodically checks your computer screen for pixel changes. If it detects any, it notifies you. You can monitor the entire display or specify zones to watch, such as the taskbar, notifications, or a terminal window. There are multiple ways to be notified of changes: sound, mobile notifications, or tray notifications. You can also fine-tune the detection with various configurations, like color threshold and pixel count. A configurable mouse jiggler is included to prevent your screen from sleeping during monitoring.

Display Monitoring consists of two applications: a desktop application and a mobile application. The desktop application is the main program that monitors your display and sends notifications. The mobile application is optional and is only needed if you want to receive notifications on your mobile. You can find download links here.

Change detection

Display Monitoring works by taking periodic screenshots of defined zones and checking for pixel changes. A "zone" is a part of the display that you can add and resize in the main application screen by dragging its corners. You can create a new zone from the "Zones/Add new" menu. Each zone has a threshold configuration that specifies how many pixels must be different to trigger a notification. For example, if you are monitoring the entire taskbar, a time change is likely an insignificant change that you can ignore by setting a higher threshold. It can be difficult to guess the right number of pixels, so it's easier to run the application and check the history to get statistics. You can read more about this in the "Notifications History" section.

Notifications

The application offers three types of notifications.

Mobile

To receive mobile notifications, you need the mobile app. You will also need to pair your mobile device with the desktop application through a registration process. Registration requires an email and a password. You can register from either the desktop or mobile application. After registration, you must log in with your user credentials on both devices. Notifications are sent from the desktop to the mobile application. You can trigger a test notification from the desktop menu via "Notifications/Send test notification" to verify the connection. If you are logged in with the same user on both applications and have an internet connection, you should receive a mobile notification. A basic account has a limit of 10 mobile notifications per day. A premium account allows for 1000 notifications per day.

Tray

A tray notification is the default way to notify users about events in Windows. If this option is enabled in the settings, the application will create a tray notification when it detects a display change. You can use all the usual tray notification features, such as "Do not disturb" and priorities.

Sound

This is the most noticeable notification, ideal for critical scenarios. If this option is enabled in the settings, the application will play a selected sound when a change is detected. You can also configure the sound to play on a loop or just once.

Notifications History

The history is a useful tool for tuning change detection to avoid false notifications and fix misconfigurations. It is shown during monitoring and can be accessed after monitoring from the "Notifications/History" menu. The history is cleared after every application restart or can be cleared manually. It is stored only in memory.

Each history record represents a single screenshot taken by the application. It shows the time the screenshot was taken, the number of pixel differences from the previous screenshot, and the notification status (i.e., if a notification was triggered and sent successfully).

If you click on a history record, you will see two tabs: a screenshot overview and a list of pixels.

The screenshot overview displays the zone screenshot with all different pixels highlighted in bright red, giving you a high-level idea of what changed in that specific zone.

The list of pixels shows every pixel that is different from the previous screenshot. It includes the exact coordinates on the screen and the previous and new colors. If you click on a pixel, you will see two images: the selected pixel in the previous screenshot and the pixel in the current screenshot.

By drilling down into each screenshot, you can determine how many pixels are different and why. If a false notification was sent, or a real notification was missed, checking the history will help you identify what is wrong with the configuration. You can then adjust the pixel threshold for that zone or the color tolerance in the settings.

Settings

The application has two types of settings: main settings for the entire application and zone-specific settings.

Main Settings

Main settings can be accessed via the "Main/Settings" menu.

Screenshot Interval

This is the interval between screenshots in seconds. Adjust it if you need screenshots more or less often.

Pixel Difference Tolerance

This configures how pixel colors are compared. It sets a +/- bracket for each color component in a single pixel. For example, if a pixel's RGB value is (50, 100, 150) and the tolerance is 5, it will consider pixels equal if the comparable pixel's R is from 45 to 55 (50 +/- 5), G is from 95 to 105, and B is from 145 to 155. For a strict pixel comparison, you can set the tolerance to 0. However, in practice, some Chrome elements change their colors slightly over time, so some tolerance is needed to ignore these changes.

Start Delay (seconds)

This is the delay after you press the "Start" button and before the first screenshot is taken. This is useful for minimizing the application window or bringing the window you want to monitor to the front. If set to 0, monitoring starts immediately.

Sending Delay (seconds)

This is the delay between a change being detected and the notification being sent. This is useful when you are stopping monitoring and want to bring the application window to the front to click "Stop". If set to 0, the notification is sent immediately.

Show Tray Icon

Shows a tray icon when the application is open. You can start and stop monitoring from the tray icon's context menu.

Minimize to Tray When Closing Window

If the tray icon is showing, closing the main window will hide it instead of closing the application. You can show the main window again by double-clicking the tray icon or from the icon's context menu.

Stop After First Notification

This will stop monitoring after the first notification is sent during a run. This helps to reduce the notification count and avoid unnecessary notifications. If not checked, notifications will be sent on every detection until monitoring is stopped manually.

Send Screenshot with Notification

For Premium accounts only. This allows you to see what is different directly from your Android device.

Use Mouse Jiggler

This is needed if you don't want your computer to go to sleep during monitoring. It will move the mouse cursor a few pixels to the right and then the same number of pixels to the left after a few seconds. It has three options: "When started" - the jiggler only works when the application is monitoring; "Always" - the jiggler is on the entire time the application is open, even if not monitoring; "Never" - the jiggler is not active, even when monitoring.

Mouse Jiggler Offset (pixels)

The number of pixels that the mouse jiggler will move the mouse to the left or right. Usually, 1 is enough to avoid sleep and is not noticeable to the user.

Mouse Jiggler Interval (seconds)

The number of seconds between the mouse jiggler moving the mouse. This should be less than your computer's sleep interval.

Autostart

Monitoring will start automatically if no user presence is detected for a configured number of seconds. User presence is detected by mouse movement.

Autostart After No Activity (seconds)

The number of seconds of inactivity to wait before starting monitoring automatically.

Autostop

Automatically stops monitoring if user presence is detected (i.e., the user moves the mouse).

Use Tray Notification

Enables tray notifications.

Use Android Notification

Enables Android notifications.

Use Sound Notification

Enables sound notifications. Requires choosing a notification sound.

Loop Sound Notification

If sound notifications are enabled and this is checked, the sound will play in a loop. Otherwise, it will play just once.

Sound Notification File

The WAV file to be used for sound notifications. It defaults to "C:\Windows\Media\", but you can browse to any file.

Zone Settings

Zone settings can be accessed via the "Zones/Show all zones" menu, then by clicking on a zone. They are specific to each zone.

Name

This is the name for each zone. A good name can be useful to quickly understand what happened, such as "John online" or "File downloaded".

Threshold

The minimum number of different pixels during a screenshot comparison that will trigger a notification.

Premium Account

A Premium account gives you 1,000 Android notifications per day (a free account has 10 per day). It also allows you to see a zone screenshot in the notification, start display monitoring from your phone, and see the desktop connection status from your phone. A Premium account costs 10 EUR per month.