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How to build a comparison from a clinical entry in Dermi Atlas and compare visits in the split layouts and the overlay layer stack, with manual adjustment, undo, and export.
A comparison holds a set of a patient's images together so they are viewed as one subject. Dermi Atlas opens the comparison in a full-screen workspace with two surfaces: a split view that places the images in adjacent sections, and an overlay view that stacks them as layers with adjustable opacity. The split view keeps each visit legible on its own; the overlay puts visits in the same frame, so a small difference between two dates reads directly.
Comparisons are built in the entry workspace, where the images documented for a visit are already gathered.
The images in the comparison are sorted by date, so the sections and layers open in visit order whatever order they were picked in. A selection that matches an existing comparison raises a "Cannot create comparison" notification instead of creating a second copy. An entry holds up to 100 comparisons.
Illustrative demo with synthetic data. Learn more
The comparison appears as a card in the Comparisons section of the entry. The header row of the card carries Compare, which opens the comparison workspace, and the Comparison Properties button, which opens the drawer. Below the header sit the thumbnail collage, the date range, the image count, a count of any comparison marks, and the Caption field. A colleague's initials appear on the card of a comparison they have open, and a caption they are editing shows their caret.
The Comparison Properties drawer holds a preview of the collage, Compare, a larger Caption field, an Effective Date field, the image count and date range, and Delete Comparison. The effective date defaults to the time the comparison is created and sets its place among the comparisons of the entry, earliest first, so changing it moves the card. Deleting a comparison asks for the phrase PERMANENTLY DELETE COMPARISON and cannot be undone or recovered; its images stay in the entry.
The workspace header carries the Split and Overlay tabs, the controls for the open tab, the sync status pill, and Rendering Settings, where display quality is balanced against responsiveness on slower devices (see Viewing Images). A comparison opens on the Split tab.
The toolbar along the bottom of the canvas holds the mode selector, Undo and Redo, the annotation Visibility control, the Image Filter control, Live Pointer, and the zoom chip, plus the split-layout control on the Split tab and the positioning commands in Arrange mode. On narrow widths the less-used items move into a More Options menu, grouped by section.
An image filter applies to every section and every layer at one strength, so the visits are read under the same rendering; see Reading Photographs with Image Filters. Live Pointer draws temporary strokes for pointing during a consultation; see Annotating Clinical Images.
While another session holds the arrangement of the same comparison, Arrange mode and the layout controls are disabled until that session closes it. Real-Time Synchronization Across Devices describes how the arrangement is shared.
The mode selector sets what a gesture on the canvas does:
Escape returns the canvas to View.
The split view divides the canvas into one section per image. Three layouts are offered from a segmented control:
Illustrative demo with synthetic data. Learn more
A caption pill at the top of each section carries the image date, controls to swap the image left or right, and the anchor that sets it as the alignment reference. The Captions control in the header shows or hides the caption pills.
The zoom chip reports the magnification and opens a slider with preset levels. In View mode the zoom applies to every section about its own center and a drag pans all of the images together, so the same detail is magnified and framed identically in each section.
Illustrative demo with synthetic data. Learn more
The Overlay tab stacks the images on one canvas, newest on top, beside a layers panel. The Layers control in the header shows or hides the panel, docked beside the canvas on wide screens and opened as a drawer on narrower ones.
Each layer card holds the thumbnail, the date, a count of any marks, the alignment reference anchor, a grip for reordering the stack, an eye toggle, a curtain toggle, and an opacity slider. Lowering the opacity of an upper layer lets the layers beneath show through.
Illustrative demo with synthetic data. Learn more
The eye toggle hides a layer, stepping the visible stack back to an earlier visit. A hidden layer keeps its position, opacity, and marks until it is shown again.
Illustrative demo with synthetic data. Learn more
The Show Curtain toggle draws a straight edge across the layer and hides the layer and the marks saved on its photograph on one side, so two visits meet along a line. Turning the curtain off shows the whole layer and keeps the edge where it was left.
Illustrative demo with synthetic data. Learn more
On the canvas in View and Arrange modes, dragging the line slides the edge across the image, dragging the pivot on the line moves the pivot and carries the edge with it, and the rotation handle turns the edge about the pivot, snapping to horizontal and vertical. When more than one layer has its curtain on, selecting one of their cards moves the line, pivot, and rotation handle to that layer, and each of the others shows a faint line where its edge lies.
Illustrative demo with synthetic data. Learn more
Illustrative demo with synthetic data. Learn more
In the overlay, the zoom chip magnifies the whole stack together, so the layers stay lined up as it grows.
Auto Align Images, in the Arrange toolbar, lines the images up against the alignment reference by matching the same anatomy across them. Automatic Alignment for Image Comparisons covers the reference, the notices, and the limits.
Illustrative demo with synthetic data. Learn more
In Arrange mode, small drags refine an alignment that is close but not exact, and each one can be undone.
Illustrative demo with synthetic data. Learn more
The reset commands sit beside Auto Align Images:
A comparison can hold an overview, a close-up, and a macro photograph of the same site. Once aligned, the shared anatomy occupies the same place in each section, and because the sections move and zoom together in View mode, the site stays in frame at every scale while the closest photograph supplies the detail. This suits a lesion documented both in context and up close, or visits photographed at different distances.
Illustrative demo with synthetic data. Learn more
Each surface keeps its own history of up to 30 steps until the page is reloaded. Undo and Redo sit next to the mode selector and answer to Command or Control with Z to undo, and Command or Control with Shift and Z, or with Y, to redo.
Moving an image, changing the layout, running Auto Align, setting the alignment reference, hiding or reordering a layer, changing its opacity, turning a curtain on or off, adjusting the curtain edge, and each reset command are separate steps. One sweep of a slider, one drag that moves a curtain edge, or one zoom in the split view is undone in one step.
A comparison is saved with the entry: the images and their order, the caption, the split layout and arrangement, the overlay arrangement, the opacity, visibility, and curtain of each layer, the alignment reference and the alignment, and the comparison marks. Reopening the comparison restores it as it was left.
Clinician accounts export a comparison from the More Options menu: Quick Export saves the comparison as arranged in one step, and Export Options opens the Export drawer with frame, filter, label, and branding choices. Both are described in Exporting Images with Custom Export.
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All demonstrations, screenshots, and media on this page use synthetic data only. No real patient information is shown.
The following are synthetic and do not correspond to real patients:
Media is provided solely to illustrate platform functionality and workflows.