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MRC PDF Kompressor 3.3

Professional document compression with Mixed Raster Content technology – up to 95% size reduction, BSI TR-Resiscan compliant.

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Screenshot of MRC PDF Kompressor 3.3

Description & documentation

Professional document compression (demo version)

The MRCCompressor is a powerful tool for converting scanned images (TIF, JPG, PNG) into extremely compact, audit-proof PDF files.

By using the Mixed Raster Content (MRC) method, the software separates text from image backgrounds. The result is documents that are up to 95% smaller than the original, while keeping the text crisp and perfectly legible.

This version uses a newly developed hybrid engine that requires no expensive commercial licences and delivers results comparable to the market leaders.

The highlights (features)

  • Extremely high compression: reduces file sizes from, e.g., 5 MB to under 100 KB (in text mode).
  • BSI TR-Resiscan compliant: uses a "pattern-safe" method (no JBIG2 symbol matching). No characters are replaced or altered. Ideal for replacement scanning.
  • Intelligent image processing:
    • Smart Inpainting: reconstructs backgrounds behind text to avoid artefacts in graphics.
    • Background Bleaching: removes grey haze and noise for pure-white backgrounds.
    • Text Sharpening: preserves the edges of coloured stamps and signatures even under strong compression.
  • PDF/A-1b support: creates long-term archivable files on request (ISO standard).
  • Split-view GUI: new interface with real-time preview (original vs. result) and synchronised zoom.
  • Batch & CLI: fully automatable via the command line for batch processing.

How it works

The tool splits the scanned image into two layers ("layering"):

  1. Text mask: the text is extracted at high resolution (300 DPI) and stored as a 1-bit graphic (CCITT G4). This guarantees maximum sharpness with minimal storage requirements.
  2. Background layer: paper structure, stamps and images are processed separately, smoothed and efficiently compressed as JPEG.
    In the final PDF, these layers are overlaid.

Instructions & operation

1. Graphical interface (GUI)
Start MrcCompressor.exe for interactive mode:

  • Load one or several images.
  • Use the sliders on the left to find the perfect balance between quality and size.
  • Or: choose between "Text Optimised" (for invoices/letters) and "Graphic Optimised" (for certificates/photos).
  • Copy the command generated at the bottom left for your scripts.
  • Save the generated PDF file.

2. Command line (CLI)
Ideal for servers or batch scripts.
Syntax: MrcCompressor.exe "Input.tif" "Output.pdf" [options]

Example:
MrcCompressor.exe "Scan01.tif" "ArchivScan01.pdf" --mode text --pdfa

Important parameters:

  • --mode [auto|text|image]: selects the algorithm (automatic, text bleaching or image preservation).
  • --pdfa: creates a PDF/A-1b file (requires srgb.icc in the folder).
  • --threshold [0-255]: sensitivity of text detection (default: 150).
  • --noblobs: automatically removes large black borders from the text mask.

When called via the command line (CMD/PowerShell), the following parameters are available:

Parameter overview for MRC Compressor

This overview describes all available settings of the MRC Compressor. They can be controlled both via the user interface (GUI) and via the command line (CLI).

The settings are stored in the file mrc_profiles.xml.

Main settings

SettingCLI parameterExplanationDefault
Mode--mode [auto/text/image]Controls the processing strategy.
Auto: automatically detects whether a page is text or graphic.
Text: optimised for sharp text, removes background details.
Image: preserves colours and photos, but needs more storage space.		Auto
Auto-Detect Threshold--autothresh [0-100]Sensitivity threshold for auto mode.
Specifies what percentage of the page must be "colourful" for it to be recognised as graphic/image.
Low (e.g. 2%): even small coloured logos switch to graphic mode.
High (e.g. 15%): only real photos switch over; documents with colour accents stay in text mode.		8%
PDF/A--pdfaCreates a PDF/A-1b compliant file (for long-term archiving). Disables transparencies.Off

MRC segmentation (mask & text)

SettingCLI parameterExplanation
Text Threshold--threshold [0-255]"Where does text end, where does background begin?"
Determines how dark a pixel must be to be recognised as text. 0 = pure black only, 255 = everything.
A higher value also detects lighter/grey text, but risks recognising dirt as text.
Colour Sensitivity--sens [0-100]Determines how sensitively the mask ignores colour differences.
A high value merges similar colours, which makes the mask cleaner ("less blotchy").
Remove blobs--noblobsWhen active, large black areas (e.g. black borders from scanning) are automatically removed and assigned to the background.
Max. text size--blobsize [px]Maximum size (in pixels) an object may have to still count as "text". Anything larger is treated as graphic/background.

Background optimisation

SettingCLI parameterExplanation
Background scaling--scale [1-10]Strongest factor for the file size.
The background is stored downscaled.
1 = original: best quality, large file.
3 = standard: background has 1/3 resolution (at 300 dpi that corresponds to 100 dpi). Usually completely sufficient for text documents, since the sharp text lies on top.
Background quality--quality [0-100]JPEG2000 compression quality of the background layer.
Low (<30): saves space, but creates "block" artefacts.
High (>70): hardly any artefacts, larger file.
Graphic preservation--bgsens [0-200]Determines how much detail should be kept in the background.
A low value "washes out" the background more (good for text scans), a high value preserves structures (good for patterned backgrounds).
Blur--blur [0-5]Applies a blur over the background. Helps to remove noise and halftone dots in the paper.
Saturation--sat [0.0-5.0]Adjusts the colour saturation of the background.
0.0: black and white (greyscale).
1.0: original.
>1.0: boosts colours (good for pale scans).
Background bleaching--white [0-255]"White point": all brightness values above this are turned to pure white (transparent).
Ideal for removing grey paper or show-through from the back ("paper cleaning").

Vectorisation

SettingCLI parameterExplanation
Vectorise--vectorizeTries to convert the recognised text into real vector graphics instead of pixels.
Advantage: infinitely sharp when zooming.
Disadvantage: can deform letters on poor scans ("O" becomes "Q").
This makes the scan no longer pattern-safe / TR-Resiscan compliant!
Keep as vector--keepvectorStores the vectors directly in the PDF (larger file, best quality). If disabled, the vectors are rasterised (smaller file).
Bake into BG--bakevectorRenders the vectors back into the background layer. Uses vectorisation only to "smooth" the edges.

Filters & effects

SettingCLI parameterExplanation
Sharpen--sharpen [0-20]Re-sharpens the background after downscaling to keep details legible.
Edge optimisation--edge [0-30]Artificially enhances edges (unsharp masking), e.g. to make signatures stand out more clearly on the background.
Colours (Posterize)--posterize [2-128]Reduces the number of colours in the background (e.g. to 16 colours). Creates a "comic look" and saves a huge amount of storage, since areas of the same colour compress better.
Watermark (only available in mrc_profiles.xml)Writes a text in semi-transparent red over the finished PDF.

Syntax

The call is made via the command line (CMD/PowerShell)

MrcCompressor.exe "Input file" "Output file" [parameters]

(If no output file is specified, the input file is saved with the extension .pdf in the same folder.)

Archiving (PDF/A):

MrcCompressor.exe "Scan.tif" "Archiv.pdf" --pdfa

System requirements

System requirements

  • Windows 10/11 (64-bit)
  • Microsoft .NET Framework 4.8 or newer
  • Visual C++ Redistributable (x64)

Download

File: mrc-pdf-kompressor.zip · Version: 3.3 · Size: 62.3 MB

Free for private and commercial use. No warranty for freedom from errors.

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