From masses to marks Open a reference. It first fits the screen. Fit adapts to the available space without changing your chosen rotation. Pinch to inspect details; drag to pan only while zoomed in. A quick inward pinch and release returns to Fit. Inspection keeps the same focal point and relative zoom across orientation changes. Use Edit crop to change the composition. The controls sit outside the image area and scroll independently. On wider screens they move into a sidebar.
The first slider reveals detail by reducing the rank filter’s square neighborhood. The percentile slider favours darks below 50 and lights above 50; 50 is the median. Optional tonal protection retains an original pixel when its value difference from the filtered candidate exceeds the threshold. This uses the current RGB value approximation; it is not edge or corner detection. Filtering uses exact per-channel 8-bit ranks with cached column histograms. Palette posterization groups the filtered image’s colors into a palette learned from that image.
Camera opens the rear camera. Your current composition becomes an independently adjustable overlay. Drag, pinch and rotate to align it with your paper, then lock its position. Filter changes remain available. Image rotation is shared between reference and camera modes; their framing is saved separately. After a camera view or device orientation change, check physical alignment and tap Alignment checked.
Every uploaded reference is immediately accepted in full: filters and guides work without a crop step. Edit crop opens an optional viewfinder with named paper proportions, portrait/landscape orientation, and a square-cell grid. The suggested format follows the image, not the screen. Drag the image beneath the fixed rectangle and pinch or use the zoom slider. The area outside it is dimmed. Apply crop replaces the composition and resets its guides; Cancel restores the previous composition and guides. Both buttons remain visible above the image. Afterwards, Fit, pan and zoom only inspect the accepted page. They never change its crop. In guide editing, use ＋ in the margins to add lines and drag a line beyond the page edge to delete it. All guide labels are fractions; ≈ denotes a rational approximation. PNG export saves the accepted page without guides.
Camera access requires browser permission and usually HTTPS or localhost. Downloaded-file support varies by browser. Filtering works offline. A fixed phone support helps keep the overlay aligned; this prototype does not track the paper automatically.
Once a reference is open, the app requests screen wake lock in both reference and camera modes and requests it again when you return to the app. The status line confirms whether it is active. Your browser or operating system can decline it, especially in battery-saving mode; HTTPS may be required. Image and settings are remembered locally when browser storage is available. Camera permission is always requested explicitly. Export saves the filtered reference crop, without the camera or controls.
Back to drawing