Convert QOI to DJVU
Max file size 100mb.
QOI vs DJVU Format Comparison
| Aspect | QOI (Source Format) | DJVU (Target Format) |
|---|---|---|
| Format Overview |
QOI
Quite OK Image Format
A modern lossless image format created in 2021 by Dominic Szablewski, designed for simplicity and speed. QOI achieves compression comparable to PNG while encoding 20-50x faster, using a minimal 300-line reference implementation. Lossless Modern |
DJVU
DjVu Document Format
A wavelet-compressed document format from AT&T Labs achieving extreme compression through IW44 wavelets and intelligent foreground/background layer separation for mixed-content images and documents. Lossy Standard |
| Technical Specifications |
Color Depth: 24-bit RGB or 32-bit RGBA Compression: Lossless run-length + hash index Transparency: Full alpha channel (RGBA) Animation: Not supported Extensions: .qoi |
Color Depth: 24-bit RGB Compression: IW44 wavelet + JB2 text Transparency: Mask layer Multi-page: Bundled documents Extensions: .djvu, .djv |
| Image Features |
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| Processing & Tools |
QOI is supported by Pillow 12+, game engines, and growing tool ecosystem.
# Python Pillow
from PIL import Image
img = Image.open('sprite.qoi')
img.save('output.png')
# qoiconv reference tool
qoiconv input.qoi output.png
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DJVU creation via DjVuLibre wavelet encoder. # Encode to DJVU c44 input.ppm output.djvu -slice 74 # Bundle pages djvm -c document.djvu p1.djvu p2.djvu # Extract info djvused file.djvu -e 'print-meta' |
| Advantages |
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| Disadvantages |
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| Common Uses |
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| Best For |
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| Version History |
Introduced: 2021 (Dominic Szablewski) Current Version: QOI 1.0 (2022) Status: Stable, growing adoption Evolution: QOI 1.0 (2021, single release specification) |
Introduced: 1996 (AT&T Labs) Current Version: DjVu 3 (2001) Status: Stable, open-source Evolution: DjVu 1 (1996) → DjVu 2 (1999) → DjVu 3 (2001) |
| Software Support |
Image Editors: GIMP (plugin), Pillow 12+, limited Web Browsers: Not natively supported OS Preview: Limited third-party viewers Mobile: Minimal support CLI Tools: qoiconv, ImageMagick, Pillow |
Viewers: DjView, WinDjView, Evince, Okular Web Browsers: Via plugin or JS viewer OS Preview: Linux native, others third-party Mobile: EBookDroid, DjVu Reader CLI Tools: DjVuLibre (c44, djvm, djvused) |
Why Convert QOI to DJVU?
QOI is designed for speed rather than compression ratio, often producing files similar in size to PNG. Converting QOI to DJVU applies wavelet compression that can achieve 80-95% size reduction, transforming fast-captured lossless images into compact archival documents.
Game developers using QOI for rapid screenshot capture during testing sessions can convert accumulated screenshots to DJVU for compact, browsable bug report documents. The multi-page capability lets you compile entire testing sessions into single navigable files.
Since QOI has limited viewer support outside of development tools, converting to DJVU provides a more widely viewable format for sharing QOI images with people who may not have QOI-compatible software installed.
QOI's alpha channel transparency is not preserved in DJVU conversion, as DJVU uses a different mask-based approach. For images where transparency is essential, consider PNG as an alternative target format.
Key Benefits of Converting QOI to DJVU:
- Significant Compression: 80-95% smaller than QOI source files
- Wider Viewability: DJVU readers are more common than QOI viewers
- Document Bundling: Package multiple screenshots into single files
- Testing Archives: Compile game testing screenshots efficiently
- Progressive Viewing: Quick preview of large screenshot collections
- Text Optimization: UI text in screenshots compressed efficiently
- Storage Savings: Reduce screenshot archive disk usage
Practical Examples
Example 1: Game QA Screenshot Archive
Scenario: A QA team captures hundreds of QOI screenshots per testing session using a fast capture system and needs compact bug report documents.
Source: test_session_042/*.qoi (200 screenshots, ~1.6 GB) Target: qa_session_042.djvu (200 pages, ~95 MB) Result: Complete test session browsable in one file, 94% smaller than QOI originals, with page navigation for developers to review reported issues.
Example 2: Procedural Art Gallery
Scenario: A generative artist produces QOI output from procedural algorithms and wants to compile a gallery document for exhibition submissions.
Source: generative_series_*.qoi (50 artworks, 2048x2048, ~400 MB) Target: generative_gallery_2026.djvu (50 pages, ~18 MB) Result: Portable gallery document for exhibition submissions, with thumbnail navigation and compact file size for email delivery.
Example 3: Embedded System Display Capture
Scenario: An embedded developer captures QOI screen dumps from IoT device displays and needs to compile firmware revision documentation.
Source: firmware_v2.3_screens/*.qoi (35 captures, 320x240) Target: firmware_v2.3_screens.djvu (35 pages, ~280 KB) Result: Complete firmware UI documentation in under 300 KB, with each screen as a navigable page, attached to firmware release notes.
Frequently Asked Questions (FAQ)
Q: Will QOI's alpha transparency be preserved?
A: No. DJVU does not support full alpha transparency. Transparent areas are rendered against a white background. If you need transparency, convert QOI to PNG instead.
Q: How much compression improvement does DJVU offer over QOI?
A: DJVU typically achieves 80-95% size reduction compared to QOI. Since QOI is lossless with modest compression, the lossy wavelet approach of DJVU produces dramatically smaller files.
Q: Is the conversion quality suitable for game asset review?
A: Yes. DJVU preserves sufficient visual quality for screenshot review, bug identification, and UI verification. Individual pixel accuracy is not maintained, but visual fidelity is excellent for reference purposes.
Q: Can I convert DJVU back to QOI?
A: You can extract raster data from DJVU and save as QOI, but the result will reflect lossy DJVU compression. The extracted image will not be identical to the original lossless QOI source.
Q: Does QOI's fast encoding speed help the conversion?
A: QOI's fast decoding means the source reading step is very quick. The conversion bottleneck is DJVU's wavelet encoding, which is more computationally intensive but still reasonably fast for typical image sizes.
Q: Should I use DJVU or PNG for archiving QOI files?
A: Use DJVU when file size is the priority and lossy compression is acceptable. Use PNG when pixel-perfect quality and transparency must be preserved. DJVU is better for document-style archival, PNG for editing-quality archival.
Q: Is QOI widely supported enough that conversion is necessary?
A: QOI has growing but limited support. DJVU has been established since 1996 with dedicated viewers on all platforms. For sharing with non-technical users, DJVU's viewer ecosystem is more accessible than QOI's.
Q: Can I batch convert an entire QOI screenshot folder?
A: Yes. Upload multiple QOI files and each is individually converted. The resulting DJVU files can be bundled into a multi-page document for organized archival.