> For the complete documentation index, see [llms.txt](https://docs.mindee.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mindee.com/v1/integration/ruby-sdk/ruby-advanced-file-operations.md).

# Advanced File Operations

> ❗️ Disclaimer: the file operations listed below do not directly manipulate the files you will pass to the library, They will instead create a copy before applying any operations, which means that the file you send may not be an exact copy of the file the server will receive. To avoid any unexpected or unwanted result, you can save a copy of the created file locally to inspect it visually before sending it.

## Image compression

The compression functionality for image files (JPEG, PNG, etc.) via the `compress!` method available on a LocalInputSource. This method allows you to reduce file size by specifying quality and dimension constraints.

Example:

```rb
# Compress an image with custom parameters.
input_source.compress!(quality: 85, max_width: 1024, max_height: 768)
```

> ⚠️ Warning: Compression alters the original image data. We strongly advise you inspect a compressed file before sending it:
>
> ```rb
> # Compress using a quality of 50%:
> input_source.compress!(quality: 50)
> input_source.write_to_file('path/to/my/compressed/file_50.jpg')
> ```

For reference, here's what the following levels of compression on this image will look like:

**Original:** ![Invoice sample](https://github.com/mindee/client-lib-test-data/blob/main/products/invoices/default_sample.jpg?raw=true)

**85% compressed:** ![85% sample](https://github.com/mindee/client-lib-test-data/blob/main/file_operations/compression/compressed_ruby_85.jpg?raw=true)

**50% compressed:** ![50% sample](https://github.com/mindee/client-lib-test-data/blob/main/file_operations/compression/compressed_ruby_50.jpg?raw=true)

**10% compressed:** ![10% sample](https://github.com/mindee/client-lib-test-data/blob/main/file_operations/compression/compressed_ruby_10.jpg?raw=true)

## PDF operations

PDF operations include both compression and fixing features. These are specifically designed to handle challenges associated with PDF files, such as large file sizes and formatting issues.

### PDF compression

> 🧪 PDF compression is an **experimental** feature that rasterizes each page of the PDF (similar to how images are compressed) to reduce its overall size.
>
> Because the process involves re-rendering the PDF’s contents, some source text may be lost or rendered differently. Use this feature with caution.

```rb
# Load a local input source.
input_file_path = "path/to/your/file.pdf"
output_file_path = "path/to/the/compressed/file.pdf"
pdf_input = Mindee::Input::Source::PathInputSource.new(input_file_path)

# We advise you test the quality value yourself, as results may vary greatly depending on the input file
pdf_input.compress!(quality: 50)

# Write the output file locally for visual checking:
File.write(output_file_path, pdf_input.io_stream.read)
```

> 🚧 Be warned that the source text (the text embedded in the PDF itself) might not render properly, and so source PDFs will be ignored by default.
>
> You can bypass this using:

```rb
pdf_input.compress!(quality: 50, force_source_text: true)
```

Or alternatively, you can try to approximate the re-rendering of the source-text using:

```rb
pdf_input.compress!(quality: 50, force_source_text: true, disable_source_text: false)
```

### PDF Repair

The PDF repair feature attempts to rescue PDFs with invalid or broken header information. This can sometimes help when files get rejected by the server.

Example:

```rb
# Load a PDF file with the repair_pdf flag enabled.
input_source = mindee_client.source_from_file(file, "document.pdf", repair_pdf: true)
```

> ⚠️ Warning: PDF fixing alters the input file by re-writing header information. Use this feature only when required, as it might affect the integrity of the document file.

***

Feel free to expand these examples and adjust the parameters as needed for your projects. For further details on authentication and usage, you can refer to the [Getting Started Guide](https://github.com/mindee/legacy-docs/blob/main/libraries/ruby-sdk/getting_started.md).


---

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