Histogram¶

Oak provides monitoring tools in the Scopes panel to help judge exposure and color distribution. The panel currently supports three scopes: Waveform, Vectorscope, and Histogram.

Opening the Scopes Panel¶

• The scopes panel is hidden by default. Open it from the Window menu or the dock-panel manager.

• Once opened, the scopes follow the currently focused viewer (Sequence Viewer or Footage Viewer).

Switching Scope Types¶

A drop-down at the top of the Scopes panel switches between:

• Waveform

• Vectorscope

• Histogram

Histogram¶

• Shows the RGB channels overlaid as a 256-level luminance distribution.

• GPU path uses the rgbhistogram.frag / rgbhistogram_secondary.frag shaders.

• Falls back to CPU statistics when the backend does not support the GPU path (for example some Vulkan paths).

Waveform¶

• Displays luminance distribution with RGB overlaid; the Y axis corresponds to image brightness.

• Overlays IRE graticule lines to judge exposure.

• GPU path uses rgbwaveform.frag / rgbwaveform.vert.

Vectorscope¶

• Displays chroma distribution.

• Overlays standard color targets (R / Mg / B / Cy / G / Yl) to judge white balance and saturation.

• GPU path uses rgbvectorscope.frag / rgbvectorscope.vert.

Color Management and Right-Click Menu¶

• The scopes analyze the image after the display transform (i.e. what the monitor shows), not the raw reference-space data.

• Right-click a scope to open the ManagedDisplayWidget menu and switch Color Space / Display / View / Look.

Limitations¶

• There is currently no separate RGB Parade scope.

• The histogram does not perform exact peak normalization; the peak display is currently an eyeball estimate and may be improved with a geometry-shader implementation later.

• The waveform is RGB overlaid; there is no independent Luma or RGB Parade toggle.