Редагувати

Поділитися через

Chroma-key effect

  • Стаття

Converts a given color plus or minus a tolerance to alpha. For example, chroma-key can remove the background of an image for a green-screen overlay effect.

The CLSID for this effect is CLSID_D2D1ChromaKey.

Example image

example of effect output

Note

In this example, the output of the chroma-key effect is the second image with the checkerboard transparent background. The third image combines this with a background image for the final green-screen overlay.

Sample code

ComPtr<ID2D1Effect> chromakeyEffect;
m_d2dContext->CreateEffect(CLSID_D2D1ChromaKey, &chromakeyEffect);
 
chromakeyEffect->SetInput(0, bitmap);
chromaKeyEffect->SetValue(D2D1_CHROMAKEY_PROP_COLOR, {0.0f, 1.0f, 0.0f, 0.0f});
chromakeyEffect->SetValue(D2D1_CHROMAKEY_PROP_TOLERANCE, 0.2f);
chromakeyEffect->SetValue(D2D1_CHROMAKEY_PROP_INVERT_ALPHA, false);
chromakeyEffect->SetValue(D2D1_CHROMAKEY_PROP_FEATHER, false);
 
m_d2dContext->BeginDraw();
m_d2dContext->DrawImage(chromakeyEffect.Get());
m_d2dContext->EndDraw();

Effect properties

The properties for the chroma-key effect are defined by the D2D1_CHROMAKEY_PROP enumeration.

Requirements

Requirement Value
Minimum supported client Windows 10 [desktop apps | Windows Store apps]
Minimum supported server Windows 10 [desktop apps | Windows Store apps]
Header d2d1effects_2.h
Library d2d1.lib, dxguid.lib