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OpenComic includes AI-powered image enhancement features that can dramatically improve the quality of low-resolution or compressed comic images. Using the opencomic-ai-bin package, you can upscale images, remove compression artifacts, and eliminate screening patterns.

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AI features overview

Upscaling

Increase image resolution 2-4× while preserving details

Descreen

Remove halftone screening patterns from scanned comics

Artifact removal

Clean up compression artifacts and noise

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AI upscaling

Upscaling uses machine learning models to intelligently increase image resolution beyond simple interpolation.

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Features

  • Scale factors: 2×, 3×, or 4× original resolution
  • Auto-scale: Automatically determines optimal scale based on target resolution
  • Noise reduction: Optional noise level adjustment (0-3)
  • Multiple models: Choose from various AI models optimized for speed or quality
  • Megapixel limit: Set maximum input size to control performance

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Available models

Default upscaling modelScales: 2×, 3×, 4×Noise levels: -1, 0, 1, 2, 3Speed: Fast to MediumBest for: General purpose upscaling with good quality-speed balance

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Configuration

1

Enable upscaling

Navigate to Reading Settings → AI Enhancement → UpscaleToggle “Active” to enable AI upscaling.
2

Select model

Choose an AI model based on your performance needs:
  • RealCUGAN: Best quality (default)
  • Lite models: Faster processing
Each model displays its relative speed (Very Fast, Fast, Medium, Slow, Very Slow).
3

Set scale factor

Choose the scale multiplier:
  • 2×: Double resolution (moderate quality gain)
  • 3×: Triple resolution (significant improvement)
  • 4×: Quadruple resolution (maximum quality)
Higher scales take longer to process.

Configure auto-scale

Enable auto-scale to let OpenComic automatically choose the best scale factor:
  • Calculates based on target megapixels
  • Prevents excessive upscaling
  • Optimizes for your display resolution

Adjust noise reduction

For models that support it, set noise reduction level (0-3):
  • -1: No noise reduction
  • 0: Minimal noise reduction
  • 1-3: Increasing noise reduction strength
6

Set megapixel limit

Configure maximum input image size:
maxMegapixels: 3.0  // Only upscale images up to 3MP
Images larger than this limit won’t be upscaled.

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Auto-scale behavior

When auto-scale is enabled: 
// Calculation formula
scale = min(max(round((√maxMegapixels / √currentMegapixels) × 2), 2), 4)

// Example: 1MP image with 3MP target
// scale = min(max(round((√3 / √1) × 2), 2), 4)
// scale = min(max(round(3.46), 2), 4) = 3

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Performance considerations

AI upscaling is computationally intensive. Processing time depends on:
  • Image resolution
  • Selected model
  • Scale factor
  • Your CPU/GPU capabilities
Optimization tips:
  • Use lower scale factors for large images
  • Enable auto-scale to prevent over-processing
  • Set appropriate megapixel limits
  • Choose faster models for real-time reading
  • Pre-process comics in advance for better experience

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Descreening

Descreening removes halftone patterns (dots/screens) commonly found in scanned print comics.

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What is screening?

Traditional print comics use halftone screening:
  • Halftone dots: Create gradients and colors through dot patterns
  • Moiré patterns: Interference patterns from scanning
  • Screen angles: Misaligned screen grids causing artifacts

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Models

OpenComic AI Descreen Hard LiteStrength: HighSpeed: MediumBest for: Heavy screening patterns, older scans

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Configuration

1

Enable descreening

Navigate to Reading Settings → AI Enhancement → DescreenToggle “Active” to enable descreening.
2

Select model

Choose between hard or soft descreening:
  • Hard: Aggressive screening removal
  • Soft: Gentle screening reduction
3

Apply

Changes apply immediately to your reading view.

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When to use descreening

Good candidates

  • Scanned print comics
  • Visible halftone patterns
  • Moiré interference
  • Older, low-quality scans

Skip descreening

  • Digital-first comics
  • Clean, high-resolution scans
  • Vector/redrawn artwork
  • Already descreened images

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Artifact removal

Remove compression artifacts, blocking, and noise from JPEG and other lossy formats.

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Common artifacts

  • JPEG blocks: 8×8 pixel compression blocks
  • Mosquito noise: Ringing around edges
  • Color banding: Posterization in gradients
  • General noise: Random pixel variations

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Model

OpenComic AI Artifact Removal Lite Speed: Medium Strength: Balanced artifact removal Best for: Compressed comic files (CBR, CBZ with JPEG images)

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Configuration

1

Enable artifact removal

Navigate to Reading Settings → AI Enhancement → Artifact RemovalToggle “Active” to enable.
2

Select model

Currently one model available (more coming in future updates).
3

Apply

Artifact removal processes images automatically while reading.

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Effectiveness

Artifact removal works best on:
  • Moderate compression: Visible but not extreme artifacts
  • JPEG images: Common in comic archives
  • Color images: Removes color fringing and banding
  • Edge artifacts: Cleans up ringing and halos
Heavily damaged or extremely compressed images may not fully recover. Artifact removal works best as preventive enhancement.

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Combining enhancements

You can enable multiple AI enhancements simultaneously:

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Processing order

1. Artifact Removal  // Clean up compression first
2. Descreen         // Remove halftone patterns
3. Upscale          // Scale up clean image
This order ensures:
  • Artifacts don’t get amplified by upscaling
  • Screening patterns removed before scaling
  • Final upscaling produces cleanest result

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Performance impact

Enabling all three features significantly increases processing time. Consider:
  • Enable only needed enhancements
  • Use faster models
  • Process important comics in advance
  • Disable for non-problematic content

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Model selection guide

  • Upscale: Lite models, scale 2×
  • Descreen: Soft model
  • Artifact removal: Lite model
  • Megapixel limit: 1.5-2.0 MP
  • Upscale: RealCUGAN, scale 3-4×
  • Descreen: Hard model
  • Artifact removal: Enabled
  • Megapixel limit: 3.0+ MP
  • Upscale: RealCUGAN with noise reduction
  • Descreen: Hard model (essential)
  • Artifact removal: Enabled
  • Noise level: 2-3
  • Upscale: Only if low-res
  • Descreen: Disabled
  • Artifact removal: Only if compressed

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Image interpolation

In addition to AI upscaling, OpenComic supports traditional interpolation methods:

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Available methods

  • lanczos3: Best quality (default)
  • lanczos2: Good quality, faster
  • mitchell: Balanced
  • cubic: Smooth gradients
  • linear: Fast, acceptable quality
  • nearest: Fastest, pixelated

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Configuration

Set interpolation method in settings:
  • Upscaling method: Used when enlarging images
  • Downscaling method: Used when shrinking images
AI upscaling bypasses interpolation methods. Set these for non-AI image scaling.

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Caching and storage

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AI processing cache

Processed images are cached: 
// Cache location
tempFolder/ai-upscale/{sha}/

// Cached files
- Original image hash
- Processed image
- Metadata

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Cache benefits

  • Skip reprocessing: Already-processed images load instantly
  • Per-comic caching: Each comic has its own cache folder
  • Persistent: Cache survives app restarts

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Cache management

OpenComic automatically manages cache size, removing old entries as needed.
Clear AI cache from settings to free disk space or force reprocessing.

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Per-page configuration

OpenComic allows different AI settings per page type:

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Page-specific settings

readingPagesConfig: {
  single: {
    readingAi: {
      upscale: { active: true, scale: 3 },
      descreen: { active: true },
      artifactRemoval: { active: true }
    }
  },
  double: {
    readingAi: {
      upscale: { active: false },  // Disable for double pages
      descreen: { active: true },
      artifactRemoval: { active: true }
    }
  },
  webtoon: {
    readingAi: {
      upscale: { active: true, scale: 2 },  // Lower scale for webtoons
      descreen: { active: false },
      artifactRemoval: { active: true }
    }
  }
}

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Benefits

  • Optimize per format: Different settings for different page types
  • Performance tuning: Disable intensive features for large pages
  • Quality control: Maximum enhancement where it matters most

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Troubleshooting

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Slow processing

1

Reduce scale factor

Lower upscale multiplier (4× → 2×)
2

Use faster models

Switch to Lite models for better performance
3

Lower megapixel limit

Process only smaller images
4

Disable features

Turn off unneeded enhancements

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Quality issues

Upscaling artifacts:
  • Try different noise reduction levels
  • Switch models
  • Lower scale factor
Over-processing:
  • Disable unnecessary features
  • Use softer descreen model
  • Reduce noise reduction

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Crashes or errors

  1. Check AI models: Ensure models are properly installed
  2. Verify system resources: Ensure sufficient RAM
  3. Update OpenComic: Latest version has performance improvements
  4. Clear cache: Remove corrupted cached files

Next: Customization

Customize themes, shortcuts, filters, and tap zones

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