Grayscale Softcopy Presentation States

Apply a GSPS on load and save the slice on screen with its window/level, zoom and annotations as a new GSPS.

A Grayscale Softcopy Presentation State (GSPS) is a separate DICOM object that records how a referenced image should be displayed (window/level, zoom and pan, annotations, shutters) without changing the image itself. dcmage reads a GSPS opened together with its image or imported into a session that has it, shows the slice it refers to and applies its window/level, zoom and graphics. It can save the slice on screen with its window/level, zoom and annotations as a new GSPS file, and it marks key images, which it exports as a Key Object Selection document.

Problem

You have a DICOM Grayscale Softcopy Presentation State (GSPS) file that defines how an image should be displayed — window/level, zoom, pan, annotations. When you load a GSPS alongside its referenced image, the viewer should automatically apply the presentation state. You also want to mark specific images as Key Images (Key Object Selection) for quick reference.

Steps

GSPS Application

1. Load the image and its GSPS (⌘O) — load test.dcm and pr-test.dcm together.

2. Verify automatic W/L application — the StatusBar should display the GSPS-defined window/level values (e.g. 800/200 for Window Width / Window Center). This proves the GSPS was parsed and applied.

3. Open a GSPS that dcmage saved together with its series, or open the series first and add the GSPS with Import. The viewport moves to the slice the GSPS refers to, with its window/level and zoom, and its measurements appear on the image and in the Annotations tab.

GSPS Export

4. Scroll to a slice and draw annotations on it — length, angle, ellipse, bidirectional, probe, arrow or Cobb angle.

5. Export → Export Viewport State (GSPS) — the saved file refers to the slice on screen and carries the window/level, the zoom, and each annotation as graphics on the MEASUREMENTS layer with its value as text, in the places the DICOM standard defines. Annotations on other images are not included. See Export viewport state.

Key Object Selection

6. Load a regular image and verify the MARK KEY button is visible in the StatusBar.

7. Click MARK KEY — the button changes to KEY IMAGE (indicating the image is now marked). Click it again to unmark (returns to MARK KEY).

Result

Loading a GSPS alongside its referenced image shows the slice it refers to and applies its window/level and zoom, with the StatusBar showing the values, and draws its graphics as annotations. An exported GSPS carries the slice on screen and its annotations, and other viewers apply its window/level and zoom. The Key Image toggle marks or unmarks the current instance, its label switching between “MARK KEY” and “KEY IMAGE”.