User manuals.

1. Du-PDF Atelier

PDF reader and annotation tools — chapters match the in-app Atelier manual.

Overview

Du-PDF Atelier is the full PDF editor you reach from the home quick-edit rail. It uses the same rich reader and annotation canvas as custom PDFs and documents opened from your library.

On entry you can import a PDF from Files (device or iCloud) or pick one already in your Imported collection. After a file is chosen, the editor opens in place — no extra navigation step.

Tap the book icon in the toolbar anytime to reopen this manual while you work.

Opening a PDF

Choose PDF from Files launches the system file picker (PDF only). DuPDF copies the file into your library and opens it in the editor.

Choose from Imported lists PDFs you previously imported — handy when you return to the same contract, form, or report.

A coach card may appear on first open with the same choices. Tap Not now to dismiss it and use the buttons on the welcome screen instead.

Canvas, zoom, and chrome

Pinch to zoom and drag to pan on the PDF page. Scroll vertically to move through the document when chrome is visible.

Scroll down on the page to hide the top and bottom toolbars for a cleaner reading view. Scroll up or tap the page to bring them back — unless you pinned toolbars in Settings.

When both bars are hidden, a slim page slider can appear at the right edge for quick jumps between pages.

Top toolbar

Continuous / Single Page toggles scroll mode: continuous flows all pages; single page shows one page at a time with chevron navigation in the bottom bar.

Dark Mode switches the reader chrome and page backdrop for comfortable night reading without changing your global app theme.

Undo and Redo walk back recent annotation and edit steps. Save writes changes to the working copy in your library.

Search finds text across the document. Export shares or saves the current PDF through the system share sheet.

Thumbnails, pages, and notes

Thumbs opens a strip of page thumbnails at the bottom — tap a page to jump there.

The center page control shows current page and total count; use the chevrons for previous and next page.

Notes opens the notes panel on the right half of the screen. Notes are tied to the document and page so you can review comments while you edit.

Annotation tools at a glance

The bottom tool strip holds six editors: Text Note, Signature, Text, Highlight, Mask, and Insert Image. Tap a tool to activate it; tap Exit (x) to return to normal reading.

Only one tool is active at a time. Switching tools may dismiss the previous tool’s panel automatically. Tool icons and labels in this manual match the colors and names shown in the reader.

Text Note

Select Text Note, then tap on the page where you want a sticky-style note anchor. Enter your note text in the editor sheet. Notes appear in the Notes panel and can be revisited per page. Use this for review comments, reminders, or markup that should stay separate from the page content.

Signature

Signature requires you to be signed in to your DuPDF account. If prompted, sign in and try again. Draw or pick a saved signature, then drag it on the page. Resize and position before confirming placement. Optional username text can appear under the signature — adjust display settings in the signature flow when offered.

Text (insert new text)

Text opens inline placement: the reader chrome hides so you can focus on typing. A text box appears at the center — drag to move, resize handles adjust the frame. Type directly on the page. Formatting controls support font size, bold, italic, alignment, and color where available in the inline toolbar. Tap Done on the text editor bar to commit the box to the PDF. Undo can revert if you change your mind before saving the document.

Highlight

Highlight activates a color palette on the right. Pick yellow, green, pink, or other preset highlighter colors. Drag across text or regions to apply semi-transparent highlight marks on the page. Change color anytime from the palette before drawing the next highlight.

Mask

Mask covers or redacts a rectangular region — useful for hiding sensitive numbers, faces, or boilerplate before sharing. Configure fill color and opacity, then place the mask on the page. Drag to move; corner handles resize; rotation controls adjust angle when shown. Confirm placement to bake the mask into the annotation layer. Save the document to persist changes.

Insert Image

Insert Image opens a picker where you can choose a photo from your library or an image file from Files. After you tap Done, drag the image preview to position it on the page, resize or rotate it with the handles, then tap Done to place it on the PDF. Use opacity and corner radius in the picker to match how the image should appear before placement.

Saving and export

Keep an independent copy of the original before editing. Save may update the library working copy; use Save As with a different name when you need a recoverable original.

Save in the top toolbar writes annotations and edits to the document’s working copy in your DuPDF library. Export opens the share sheet so you can AirDrop, email, or save to Files. Exported files include your current edits.

If save fails, check free storage and file permissions, then try again — in-memory edits remain until you leave the reader.

Efficiency tips

• Pin top and bottom toolbars in Settings if you prefer controls always visible while reviewing long contracts.
• Use Imported for files you revisit often — Atelier opens them instantly without browsing Files again.
• Search before manually scrolling multi-hundred-page PDFs; pair highlights with notes for review workflows.
• Save before Export when you want the library copy and the shared file to match.

2. Du-Image Studio

User manual — icons match the tools in the editor.

Overview

Du-Image Studio is the full-screen editor for photos you open from the home rail or your library. Work at preview speed while you adjust; many operations apply full-quality processing when you finish a gesture or release a slider.

Use the save icon in the top toolbar for Save Changes and Save As — only the image you see now is written, not your undo history. The “…” menu has Reset Zoom and Reset Edits. The bottom tool strip stays available; tap a tool again to collapse its panel back to the main row.

When several photos live in the same folder, side chevrons let you move between them without leaving the editor.

Canvas, zoom, and chrome

Pinch to zoom and drag to pan when zoomed in; edges clamp so you never lose the picture off-screen. Tap the image to hide or show the top navigation bar — handy for judging composition. The bottom tool strip stays visible so you can keep editing. The editor uses a dark stage behind your photo so exposure and filter judgments stay consistent.

Brightness, contrast, and saturation

Open Brightness, Contrast, or Saturation from the main strip. Drag the slider for a live preview on a downscaled working copy so motion stays fluid. When you release the slider, Du-Image applies the same settings to the full-resolution bitmap so exports stay sharp. Use Reset Edits in the “…” menu to snap all color controls (and related filters) back to a clean baseline.

Rotate and mirror

Rotate exposes preset angles (including 90° / 180° / 270° style steps, depending on layout) so you can straighten scans or re-frame quickly. Mirror horizontal flips the image left-right without changing the numeric rotation angle — useful for selfies and mirrored documents. Rotation and mirror participate in the same preview → full-resolution path as the color sliders.

How filters stack (doc + image + color)

Du-Image applies adjustments in a fixed pipeline so results stay predictable: document-style treatments (when selected) run on the original geometry, then classic photo filters (Chrome, Noir, etc.), then brightness / contrast / saturation on top.

Because the pipeline is ordered, you can think “clean up the page → add a look → fine-tune exposure.” If something feels too strong, step back one stage — for example set the photo filter to Original before pushing color harder. Document filters are tuned for scans and paperwork; photo filters behave like familiar still-camera styles. Combining both is supported — watch contrast when stacking aggressive choices.

Crop tools at a glance

Under Crop you’ll see four entry points: Doc Crop, Freehand, Polygon, and Shape. Each opens a dedicated sheet optimized for that geometry. All crop sheets Cancel without changes or Apply / Done to commit; committing replaces the working image. Use the toolbar save icon when you are ready to write the file. After any crop, you can still use filters and color tools — they operate on the new pixels.

Doc Crop (four corners + perspective)

Best for pages, receipts, and photos of rectangular documents. You get four draggable corners plus optional edge adjustments on the quad. Auto Detect runs Vision rectangle detection to snap the quad to strong edges — great on high-contrast pages. You can always tweak corners afterward. Perspective correction flattens the quad into a frontal view when enabled — ideal for shots taken at an angle. Grid overlays alignment lines; Magnifier enlarges the active corner while you drag for pixel-accurate placement. Reset returns to a safe default frame inside the image if you want to start over without leaving the sheet.

Freehand crop

Draw continuously with your finger; the path samples points while respecting a minimum spacing so strokes stay smooth. Move close to your starting point to close the path (within the on-screen tolerance). Until the path is closed you’re still defining the region. Suited for irregular cut-outs where a rectangle won’t do — logos, torn edges, or creative shapes. Undo/clear controls (when shown) help recover from mistakes without leaving the sheet.

Polygon crop (tap-to-add vertices)

Tap anywhere on the photo to drop vertices in order. You need at least three points before the shape can close. After three points, move near the first vertex (highlighted in green) to close the polygon — the editor shows a generous hit zone so closing feels forgiving. Before closing, Undo removes the last point and Clear wipes all points so you can restart quickly. Once closed, the outline shows a cut-out mask preview. Drag any vertex to fine-tune; positions clamp to the image bounds so you never pull handles off the bitmap. This mode shines when you need many corners — floor plans, property lots, signage, or any boundary that’s straight segment-by-segment but not a rectangle.

Shape — rectangles, triangles, and handles

Shape opens the advanced cropper with a shape picker along the bottom: Rectangle, Circle, Elliptical, Triangle, L-shape, T-shape, Cup, and Polygon presets.

Rectangle, elliptical, and circle use corner, edge, or radius handles similar to other pro editors — drag handles or move the whole region from the center hit target when available. Elliptical crop uses independent width and height (oval), not a fixed circle radius.

Triangle (three-point geometry): when exactly three corners are active, edge handles use a similar-triangle drag model: dragging an edge scales the shape from the opposite vertex so interior angles stay locked while you resize. That keeps triangles geometrically consistent without skewing angles unintentionally.

L, T, Cup, and Polygon presets expose vertex and edge controls tuned to each topology — drag vertices for local reshaping, use edge bars where shown to adjust spans while preserving the intended constraint model for that silhouette. Switch shapes from the picker anytime; the cropper reinitializes vertices for the new geometry. Confirm with the sheet’s primary action to bake the crop into your image.

Filter tools (focused workspace)

Tap Filter on the main strip to open the four filter types: Remove BG, White BG, classic Filters, and Face. Only that picker shows — your image keeps maximum room. Choose a type to enter a focused panel with just that tool’s controls. Face adds one more step: pick Smooth, Whiten, or Makeup, then only the slider shows. Use ← Face to return to those chips, ← Filters for the four-type picker, or ← Tools for the main strip. Tap Filter on the main strip again while browsing types to exit filter mode entirely.

Saving and naming

Save Changes writes over the imported working copy according to your existing save rules (and may update Photos / library helpers where enabled). Save As lets you choose a new filename or location when you need duplicates or variants. If an error sheet appears, read the message — usually permission, disk space, or an invalid format. Fix the issue and try again without losing your in-memory edits until you dismiss the editor.

Efficiency tips

• Start with Doc Crop or Shape (rectangle) for axis-aligned content, then escalate to Polygon or Freehand only when the boundary truly needs it.
• Use Auto Detect on doc shots with clear paper edges before spending time on manual corners.
• Filter mode hides the main tool strip while you work — use the back chips to navigate without stacking three rows of icons.
• When stacking filters, tweak brightness last — it’s the fastest way to recover headroom after stylized looks.

3. Inline Text Editor

User manual — matches the Edit Window in the PDF reader.

Overview

The Inline Text Editor is DuPDF’s rich Edit Window for placing new text on a PDF page. It opens when you choose the Text tool in Du-PDF Atelier or the reader and tap to add a text box. You type directly in a floating window over the page. Formatting, lists, and tables are applied before the text is committed to the PDF as an annotation. What you see in the Edit Window matches how text will appear on the page at the current zoom (WYSIWYG).

Edit Window controls

The blue-purple Edit Window header can be dragged to move the whole editor on screen. Use the gray drag handle on the toolbar for the same purpose. Cancel discards this editing session and closes the window. Undo and Redo step through typing and formatting changes (up to a deep history while you edit). Resize & Drop commits your text and returns you to placement mode so you can position and resize the box on the PDF. You must enter some text first; close any open color panels if the button stays disabled.

Fonts and character style

Bold (B), Italic (I), and Underline (U) apply to selected text or to what you type next. Tap again to turn a style off. Alignment buttons set left, center, right, or justified text for the current paragraph or selection. The font picker lists professional and decorative faces (Times, Helvetica, Georgia, and more). The size chip opens a horizontal list of preset point sizes from 10 through 48.

Text and background color

Text Color supports Auto (contrasts with the box background) or Manual palette picks. Auto is helpful on colored highlight-style backgrounds. Background Color sets the fill behind your text with an opacity slider — use it for labels, callouts, or readable overlays on busy pages. When a color panel is open, the text box may shrink so Cancel and Resize & Drop stay reachable; close the panel to expand the editing area again.

Line and paragraph spacing

Line spacing adjusts the gap between lines within a paragraph — useful for multi-line blocks and form labels. Paragraph spacing adds space before or after paragraphs when you need clearer separation between blocks. Only one spacing or color panel is shown at a time; opening a new picker closes the previous one.

Lists and bullets

The list button opens List & Bullets with bullet, numbered, and related styles. Pick a style to start a list at the insertion point. While a list is active, Remove List Formatting clears list structure from the current content without deleting your text. List formatting works alongside bold, italic, and font changes on the same lines.

Tables

Tap the table button to choose row and column counts, then insert a table into the text box. Tap a table to select it; drag to move and use resize handles to change its footprint on the page. Cell-level formatting follows the same toolbar when a cell is focused. Table settings may expand the text box automatically so controls and the grid stay visible.

Placing text on the PDF

After Resize & Drop, drag the text box on the page and use corner handles to resize. Pinch-zoom on the PDF does not change committed font size — the editor preview already accounts for zoom. Confirm placement to bake the text into the document layer. Use the reader’s Undo if you change your mind before saving the PDF. Save the document from the reader toolbar so your text annotations persist in your library copy.

Efficiency tips

• Select text before changing font or color to update only that range; with no selection, changes apply to new typing.
• Use Auto text color on tinted backgrounds, then switch to Manual for brand-specific ink colors.
• Close color pickers before Resize & Drop — the editor reminds you if panels block commit.
• For long copy, expand the text box when offered (e.g. while editing tables) so you can see more lines at once.

4. Edit PDF Text (Beta)

Type slowly. Wait about 1–2 seconds after every letter before typing the next one. This gives the editor enough time to place each character in the right spot.

Place the caret (cursor) by hand. Tap to position the caret exactly where you want it — including between words and inside the spaces you add. The cursor does not always land there on its own, so set it manually.

Spaces are removable with Backspace. Any spaces you add during this editing session can be deleted directly with the Backspace key, just like normal text.

Undo and redo cover up to the last 10 committed edits, which is not a substitute for keeping an original copy. Use Save As with a different name before experimenting. Saving over a PDF under the same name may make unwanted changes irreversible.

For tips on Create PDF, see the Du-PDF Atelier manual above.