This tab allows zooming and panning the image area within the dimensions supported by the camera pixel array size.
This value shows the current zoom factor.
It cannot be modified manually but only through the Zoom in, Zoom out or Full buttons.
The value is given in % of the maximum pixel array size.
This value can be adjusted.
It specifies the step size by which every click on Zoom in or Zoom out will change the Current zoom factor.
This rectangle, given in pixels, shows the visible area for cases where resolutions (see Configuration) are chosen which exceed these limits.
The rectangle is given as tuple (x_offset, y_offset, width, height).
This shows the scaler crop rectangle which is currently active for the live view and which can be set in the Configuration.
Often, the live stream shows only a smaller window compared to the sensor's pixel array size.
Therefore, zooming in may not be immediately seen in the live view as long as the Current ScalerCrop (Live View) is inside the Current ScalerCrop (Zoom) area.
The Current ScalerCrop (Live View) is the base for determining offset and size of the Autofocus Windows when drawing rectangles on the canvas (see Focus).
Pushing the Draw button will switch into graphical mode where the zoom window can be drawn on a canvas over the Live Stream area.
All other buttons, except Full will be disabled in this mode.
Attention: With Safari (e.g. on an iPad), due to the issue with onload events, the canvas will not be directly visible. It needs to trigger window resize by shortly 'pulling' down the window.
While drawing a rectangle for the intended image section, the original aspect ratio will be preserved.
After drawing is finished, the Current ScalerCrop (Zoom) will be updated with offset and dimensions of the zoom window.
After pressing Draw, the button has changed to Submit which must be pressed in order to apply the ScalerCrop setting to the preview and store it for later photo or video taking.
Pressing Submit terminates the graphic mode.
When the Full button is pressed in the graphic mode, the dialog returns to normal mode without applying a previously drawn zoom window.
Note:
Usually, raspiCamSrv starts with a 640x[width] live view with the aspect ratio of the pixel array size. This does not cover the entire sensor range.
In order to see the full range in the live view, you need to select a sensor mode with a larger size in the Live View configuration.