> For the complete documentation index, see [llms.txt](https://docs.augelab.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.augelab.com/function-blocks/blocks-reference/input-output/outputs-exports/image-logger.md).

# Image Logger

This function block saves incoming image frames to disk with configurable file naming, format and storage limits. Use it to capture and archive images when a trigger signal is received, or to periodically dump images for inspection.

## 📥 Inputs <a href="#inputs" id="inputs"></a>

`Folder Path` - Destination folder where images will be saved. Provide a valid path.

`File Name` - Optional file name. If empty, a timestamp-based name will be used.

`Image Limit` - Optional maximum number of images to keep in the folder. When the limit is exceeded, the oldest images are removed.

`Input Image` - Image data to be saved. Connect any image-producing block to this input.

`Trigger` - Boolean trigger that controls saving. When the trigger condition is active, the image will be written according to the configured settings.

## 📤 Outputs <a href="#outputs" id="outputs"></a>

This function block does not produce any outputs.

## 🕹️ Controls <a href="#controls" id="controls"></a>

`Save Mode` - Dropdown control to choose between `Full Size` (PNG) and `Compressed` (JPEG) saving modes. Compressed mode reduces file size at the cost of quality.

## 🎨 Features <a href="#features" id="features"></a>

* Automatic timestamp naming when `File Name` is not provided.
* Optional image compression to reduce disk usage.
* Folder image count limit with automatic deletion of oldest files to enforce the limit.
* Works with any incoming image source (cameras, loaders, or processed images).
* Clear error and info messages are logged when saving succeeds or fails.

## 📝 Usage Instructions <a href="#usage" id="usage"></a>

1. Set the destination by providing `Folder Path` or use a block that supplies it.
2. Optionally provide a `File Name`; leave empty to use an automatic timestamp name.
3. Optionally set `Image Limit` to control how many images are kept in the folder.
4. Connect an image source to `Input Image`.
5. Use `Trigger` to control when images are written. Toggle the trigger to save the current image.
6. Choose the desired `Save Mode` for PNG or compressed JPEG output.

## 📊 Evaluation <a href="#evaluation" id="evaluation"></a>

When the block receives a valid `Input Image` and the `Trigger` condition is satisfied, it attempts to save the image to the provided `Folder Path` using the chosen `Save Mode`. If the folder contains more images than `Image Limit`, the oldest files are removed to respect the limit. Informational messages indicate success; error messages explain failures (invalid path, write permissions, etc.).

## 💡 Tips and Tricks <a href="#tips-and-tricks" id="tips-and-tricks"></a>

* Use `Choose Folder` to let users visually pick the target folder and feed it into `Folder Path`.
* Use `Date-Time` (timestamp) together with `File Name` to create human-readable names for chronological sorting.
* Preview images before saving by sending the same image to `Show Image` so you can inspect frames visually.
* Reduce disk usage by adding an `Image Resizer` before this block to downscale very large images prior to saving.
* When capturing from live sources, combine with `Camera USB`, `Camera IP (ONVIF)`, or `Stream Reader` as the image provider to archive frames from cameras or streams.
* If you need structured metadata alongside files, send detection/measurement outputs to `CSV Export` to log details (file name, timestamp, counts).
* Use `File/Folder Operations` to create folders or manage saved files programmatically before or after logging.
* For application flows that write multiple images at once, consider `Multi Image Write` or `Image Write` blocks as alternatives when you need different naming or trigger behaviour.

## 🛠️ Troubleshooting <a href="#troubleshooting" id="troubleshooting"></a>

* Invalid folder errors: check that `Folder Path` exists and the application has write permissions. Use `File/Folder Operations` to create required folders first.
* No image saved: verify that `Input Image` is connected and that `Trigger` is active when you expect a save.
* Images accumulate too many files: set a reasonable `Image Limit` or run a cleanup routine using `File/Folder Operations`.
* Large files slow down saving: switch `Save Mode` to `Compressed` or add an `Image Resizer` upstream.
* If filenames collide, include a timestamp (via `Date-Time`) or an index to ensure unique names.