SuiSuiView — Image & Comic Viewer for Windows

Read local images and comics with the picture and controls you prefer.

Image and comic viewer for Windows with Anime4K and other GPU upscalers, customizable controls, smart two-page reading, and ZIP/CBZ support. Open image folders and read in single-page, two-page or continuous vertical view.

한국어: 화질부터 조작까지, 내 취향대로 보는 Windows 이미지·만화 뷰어. SuiSuiView는 폴더·ZIP·CBZ를 열어 한 페이지·두 페이지·세로 연속 보기로 읽고, Anime4K·CuNNy·ACNet 등의 확대 방식과 단축키·마우스 동작을 고를 수 있습니다. GPU 업스케일링은 GPU 가속을 켜고 앱을 다시 시작한 뒤 화면 맞춤 모드에서 사용합니다. 앱 UI는 영어·한국어를 지원합니다.

Explore SuiSuiView: English · 한국어 · 日本語 · 简体中文

Availability

Alpha — source builds only. There are no public executable releases or Microsoft Store listing yet. You can build from source and report feedback on GitHub.

Free GitHub executables and a paid Microsoft Store edition are planned around the same core viewer. GitHub downloads will be updated manually; the Store edition is intended to offer installation convenience and support continued development. Store-managed updates depend on the final package. A release date and price have not been announced. The free edition will not be a trial or a feature-limited viewer.

현재는 소스 빌드로만 사용할 수 있는 Alpha 단계입니다. 무료 GitHub 실행 파일과 유료 Microsoft Store 배포는 준비 중이며, 두 경로에서 같은 핵심 뷰어를 제공할 계획입니다.

The reading samples were made for this project and opened in the actual app.

Why SuiSuiView?

Focus	What it means
Choose the enlargement	Use Anime4K v3.2 CNN x2 S/M, CuNNy or ACNet variants for fit-mode display enlargement with GPU acceleration. CPU upscale filters are also selectable.
Make the controls yours	Set keyboard and mouse bindings, choose top-bar scaler quick picks, and adjust scrolling and page-turn behavior.
Read local files	Open image folders, .zip and .cbz without unpacking them yourself; switch between single-page, two-page and vertical reading.
Keep your place	Reading progress and manual bookmarks use the contents of a ZIP/CBZ as its identity, so renaming or moving the same archive keeps them.

GPU acceleration is optional and requires an app restart when switched. GPU upscaling applies to fit-page, fit-width and fit-height enlargement, not every manual zoom level. Results and processing cost depend on the image, settings and hardware. ArtCNN options are experimental. Upscaling changes the displayed image; it does not overwrite the original or export enlarged files.

The movable Adjustments / 보정 window provides gamma, brightness, contrast, black and white points, filter strength, inversion, and advanced quality controls. Corrections are saved globally across books and restarts; rotation and flips reset when changing books. Hold the bypass button to inspect the uncorrected image. The source files are never changed.

Build From Source

On Windows, install:

1. Git for Windows.
2. Visual Studio Build Tools with Desktop development with C++, including the MSVC C++ build tools and a Windows SDK. The default build compiles bundled native libraries as well as Rust code.
3. Rust through rustup, using the stable MSVC toolchain (stable-x86_64-pc-windows-msvc for Windows x64).

Open a new PowerShell window after installation, then run:

git clone https://github.com/BK927/SuiSuiView.git
cd SuiSuiView
cargo run --release --locked

The first build downloads dependencies and can take several minutes. If the linker or C++ tools cannot be found, use the Developer PowerShell for Visual Studio installed with the build tools. The executable is created at target/release/suisuiview.exe and can be opened directly after the build.

The default build includes still WebP decoding. Optional AVIF and PDF-compatible Illustrator previews need additional dependencies and are not enabled by this command. Use a release build when evaluating responsiveness.

Press F2 / Ctrl+O to open an image or archive, or F to open a folder. To try GPU upscaling, open Settings with F5, enable GPU acceleration in Rendering, restart the app, then select an upscaler and a fit mode.

Open And Read

• F2 or Ctrl+O: open a file.
• F: open a folder.
• Drag and drop: open a file or folder directly.
• PgDn, Down, Right, or Space: next page.
• PgUp, Up, Left, Backspace, or Shift+Space: previous page.
• 1, 9, or Z: fit page.
• 8: fit width.
• 7: two-page left-to-right.
• 6: two-page right-to-left.
• F5: settings.
• F1: app information and third-party open-source notices.

Right-click opens a context menu with common open, navigation, view, processing, delete, copy, and window actions.

When [ or ] opens a neighboring book, the current view mode carries over if that book does not already have a saved reading position.

Supported Files

Tier	Formats
Built in	Folders, single images, .zip, .cbz, .jpg, .jpeg, .jpe, .jfif, .png, .apng, .webp, .bmp, .dib, .gif, .tif, .tiff, .tga, .pnm, .pbm, .pgm, .ppm, .ico, .qoi, .psd
Experimental decoders included	.dds, .exr, .hdr, .rgbe; compatibility varies and HDR display output is not supported
Optional builds only	.avif with native-avif; PDF-compatible .ai first-page preview with native-ai and an app-local PDFium library
Not currently supported	.jxl, .svg, .svgz, .heic, .heif, .hif, .jxr, .wdp, .hdp, RAW/DNG camera formats, .pdf, .rar, .cbr, .7z, .cb7, .clip, .bpg

PSD shows a flattened composite preview, not layers or Photoshop effects. Optional .ai support does not add general PDF reading. Some unsupported file extensions are recognized to explain why they cannot be opened; installing a system codec does not currently enable HEIC or RAW viewing. Animated APNG, GIF, and WebP files open as still previews; animation playback is not supported.

Decoder Settings

Auto Fast selects the app's validated fast paths and falls back when needed. Compatibility mode keeps the conservative baseline, and Custom mode lets you override individual formats from Settings.

Still WebP support, including the native libwebp backend, is enabled by default. AVIF and PDF-compatible .ai preview backends are optional and off by default.

Settings

F5 opens the settings window. Settings and window state are saved to state.json; each book's reading position and page bookmarks live in their own per-book file.

• General: UI language, in-app delete confirmation, ESC exit, always-on-top, and first/last page behavior; Ask prompts auto-dismiss unless hovered.
• Rendering: transition effect, fast sampled/scaled decode, GPU acceleration, scaler/filter controls, EXIF orientation, embedded ICC conversion, prefetch, and a total memory budget (Saver/Standard/Ample presets, an automatic renderer-aware default, or a manual limit) with an estimate of cached display-image and GPU texture bytes. This is not total process RAM or physical VRAM usage. Manifest-backed SR Lab SPAN x2 is available as a slow manual GPU upscaler when local SPAN weights are present. Fixed 2x GPU SR upscalers skip tiny enlargements, can auto-stack once for large enlargement, and use the selected WGPU downscaler when their 2x/4x output is larger than the final display size. The defaults remain CPU CatmullRom and GPU Pyramid Lanczos3. The adjustment window also offers CPU Mitchell/Lanczos3 and GPU Pyramid Mitchell/Hamming, with linear-light scaling. GPU debanding offers Off/Weak/Medium/Strong and custom strength, radius, grain, and iteration controls. The scaler tooltip reports the active path and bypasses. Upscalers can be browsed as Recommended, All (grouped by family), or Experimental; existing toolbar quick picks remain available. Cache cleanup preserves images needed by the current frame and reusable quality-processing buffers; nearby texture preparation follows the active display path to avoid uploading unused copies.
• Decoders: Custom mode expands per-format decoder and fast-preparation choices. JPEG, PNG, WebP, BMP, and GIF can follow the global fast-preparation switch or be enabled/disabled individually. A disabled global switch always wins. Image information reports the actual decoder and preparation path.
• File links: on Windows, register SuiSuiView as a Default Apps candidate for selected image and comic file types.
• View, keyboard, and mouse: visible viewer UI, top-bar scaler quick picks, customizable keyboard shortcuts, double-click maximize, middle-click fullscreen, and wheel behavior.

Fast sampled/scaled decode is enabled by default. It lets large JPEG, WebP, PNG, BMP, and GIF pages use format-specific display-sized preparation before falling back to full decode plus the selected CPU downscale filter. Original-size PNG row decoding is independent of these display-preparation switches.

The UI language can be set to system default, Korean, or English. UI text and state words such as Default, Off, and Experimental are localized, while technical names such as JPEG and ZIP/CBZ stay in English.

Comparison And Output Quality

Comparison uses the same prepared page, orientation, pan, and physical display scale as the normal viewer. A and B start from the current corrections and can be edited independently. Wipe and side-by-side views share navigation. Auto is frozen at the result present when comparison opens; these temporary values are not saved as presets. The loupe magnifies a cached complete display result. Moving it does not decode the source or run full SR again, and its size does not reduce the cost of preparing that result. These model comparisons require WGPU.

Display first, replace when refined is optional and off by default. With a supported manually selected Anime4K, CuNNy, ACNet, or configured SPAN model, it shows a complete FSR1 EASU+RCAS image using the same debanding and color controls, then replaces it after the selected model finishes. It resumes GPU batches after 150 ms without input, keeps only the current requests, and replaces a two-page spread together. If the memory allowance is insufficient it keeps the fast image and reports the reason. Auto retains its existing first-display behavior.

Optional SDR monitor color management uses the Windows default display-profile policy. WGPU applies an lcms2-derived LUT after the image, background and UI have been composited. Monitor changes affect only this output stage. Clipboard images remain in the sRGB working space. Missing or unusable profiles fall back with a status explanation. HDR output and original wide-gamut preservation are outside this feature.

For automated GUI checks, set SUISUIVIEW_PROFILE_DIR to an absolute dedicated test-profile directory. An invalid or redirected path aborts startup instead of falling back to personal settings. Test instances use a separate instance scope; state, book records, and thumbnail caches stay under that directory.

Bookmarks And State

The bookmark list and its total count load in the background. Loading thumbnails show a spinner, and search edits reuse the loaded list. Next/previous-file discovery and file reading also run in the background, with an opening indicator while the current page remains visible. A sleeping or busy disk can still delay the result; image quality and the bookmark storage format are unchanged.

Rapid next/previous-file taps are kept in order and shown one book at a time. Releasing a held key cancels its queued automatic repeats; separate taps remain queued and may finish after release. While another book is opening or reserved, the current book's off-screen page prefetch pauses. First-page preparation uses the destination book's saved view and the active renderer's decode policy so a compatible prepared image can be reused. These paths keep the existing image quality and image-cache budgets.

Page requests reuse compatible reads that have already finished. Prefetch checks whether prepared pixels still exist, and completed pages waiting for the UI have a byte limit that also covers deferred processing. Navigation and shutdown commands remain available while delivery waits for room. A single page larger than that limit can still be delivered to preserve display quality.

State is saved to the platform data directory. On Windows this resolves to an AppData SuiSuiView/ folder: state.json holds settings and window state, and each book's data lives in its own file under books/.

Two things are remembered per book:

• Reading position ("이어보기"/resume) is saved automatically as you turn pages, so reopening a book returns to where you left off. It can be disabled in settings.
• Manual page bookmarks are toggled explicitly and listed in the bookmark popover.

For ZIP and CBZ files, the per-book key is based on archive contents, not the archive path, so moving or renaming the same archive keeps your place and its bookmarks.

• B: toggle a bookmark for the current page.
• Ctrl+B: open the bookmark popover.

View effects are intentionally not saved. Opening or closing a book resets rotation, flips, filters, gamma, and inversion.

Delete And Clipboard

• Delete: move the current file to the Recycle Bin.
• Shift+Delete: permanently delete after confirmation.
• Ctrl+Enter: reveal the current file.
• Ctrl+C: copy the current page image.
• Ctrl+Alt+C: copy the visible spread image.
• Ctrl+Alt+Shift+C: copy the page path.

Delete actions operate on real files only. For ZIP and CBZ, the delete target is the whole archive file, never an internal page. For folders and single images, the target is the current image file.

For ZIP and CBZ books, copied page paths use a virtual form such as book.cbz::chapter/page001.jpg because archive-internal pages are not standalone files.

Roadmap

• Native image and comic viewer.
• Folder, ZIP, and CBZ support.
• Path-independent ZIP/CBZ bookmarks.
• Large-image preview, cache, and display preparation.
• Display effects, fit-mode upscaling, and user-selectable decoders.
• Current-page EXIF, file, and color information.
• CBR/RAR and 7Z/CB7 read-only archive support.
• Webtoon-style continuous vertical reading mode.
• Folder and page thumbnail overview for faster navigation.
• Smarter Auto upscaler selection for content-aware fit-mode enlargement (per-book round-trip probe: each book's own pixels pick the winner once, cached in the book record).
• Modern format expansion, including JPEG XL, HEIC/HEIF, SVG, JPEG XR, and broader RAW preview support.
• Clip Studio Paint (.clip) flattened preview, reusing the same embedded-preview path as PSD.
• Show AI generation metadata (Stable Diffusion prompt / parameters) in the current-page info panel when present.
• WGPU comparison loupe: magnify the processed region under the cursor without changing the overall fit or zoom.
• Global brightness and contrast adjustment for dark or aged scans, alongside the existing gamma, sharpen, and smooth effects.
• Printing, slideshow, and external editor workflows.
• Long-term: HDR display output for HDR-capable formats and monitors.

Keyboard And Mouse Reference

Open And Window

• F2 or Ctrl+O: open a file.
• F: open a folder.
• F4: close the current book.
• Esc: close an open settings or information window first; otherwise exit when enabled in settings. While recording a shortcut, cancel recording first.
• X or Ctrl+W: exit.
• F11, Alt+Enter, or N: fullscreen.
• M: maximize or restore.
• Q: minimize.
• Ctrl+A: always on top.

Page Movement

• PgDn, Down, Right, or Space: next page.
• PgUp, Up, Left, Backspace, or Shift+Space: previous page.
• Home / End: first or last page.
• Ctrl+PgDn / Ctrl+PgUp: jump 10 pages.
• Ctrl+Shift+Right / Ctrl+Shift+Left: jump 100 pages.
• Shift+PgDn / Shift+PgUp: force a one-page move in two-page mode.
• Ctrl+Alt+PgDn / Ctrl+Alt+PgUp: random page.
• ] / [: open the next or previous folder, ZIP, or CBZ beside the current book. The current view mode carries over when the target book has no saved reading position.

View

• 0 or *: original size.
• 1, 9, or Z: fit page.
• 8: fit width.
• 7: two-page left-to-right.
• 6: two-page right-to-left.
• 2: toggle two-page mode.
• The view selector also includes fit height.
• + / -: zoom in or out.
• Ctrl++ / Ctrl+-: change zoom by 1%.

Display Effects

• Ctrl+I: invert colors.
• Ctrl+M: flip horizontal.
• Ctrl+F: flip vertical.
• Ctrl+L / Ctrl+R: rotate left or right.
• Alt+Up, Alt+Left, Alt+Right, Alt+Down: set rotation.
• U, I, S: change display filter.
• Ctrl+G: toggle gamma correction.

The top-bar compare toggle opens a shared-scale A/B view of the actual display chain. Both sides start from the current settings. Select existing Anime4K, CuNNy, ACNet, ArtCNN, configured SPAN or other available methods independently; missing or unsupported choices show a reason. Wipe, synchronized side-by-side viewing, and the cached-result loupe are available in the comparison controls.

Mouse

• Drag to pan.
• Mouse wheel moves pages by default.
• Ctrl+mouse wheel: zoom.
• Double-click: maximize or restore.
• Middle-click: fullscreen.
• Ctrl+middle-click: return to 100%.

Optional Stall Diagnostics

Support builds compiled with --features stall-diagnostics can record slow operations locally when SUISUIVIEW_STALL_LOG names a new absolute output file. Create its parent directory first. Without that environment variable, diagnostics stay off; default builds compile the instrumentation out entirely.

Close all running SuiSuiView windows before starting a diagnostic session. If your support build includes start-stall-diagnostics.cmd, double-click it beside suisuiview.exe, use the viewer normally, then close the viewer. Its stall-diagnostics folder contains the new report. Starting the executable directly returns to normal operation without recording.

The report contains fixed operation names, UI/background roles and relative timings, plus session and dropped-sample markers. It excludes file names, paths, book IDs, page numbers, settings, image contents and error text. Nothing is uploaded. Completed operations taking at least 100 ms are recorded; an independent worker also samples operations still running after one second. Each session is limited to 2 MiB. Existing reports are never overwritten. Use an SSD destination when investigating HDD idle/wake behavior so diagnostic writes do not wake that HDD. These timings identify where time was spent; a slow background operation alone does not establish that the UI was unresponsive.

License

SuiSuiView is licensed under GPL-3.0-only. See LICENSE and third-party notices. The planned free GitHub and paid Microsoft Store editions use the same core open-source viewer; neither executable distribution is publicly available yet. See Availability.