Document DWAA/DWAB compression in Technical Introduction (#1420)

Signed-off-by: Cary Phillips <[email protected]>

Author: cary-ilm

docs/TechnicalIntroduction.rst

@@ -824,6 +824,19 @@ Supported compression schemes:
 
        Note: This lossy compression scheme is not supported in deep files.
 
+   * - DWAA (lossy)
+
+     - Lossy compression of RGB data by quantizing discrete cosine
+       transorm (DCT) components, in blocks of 32 scanlines. More
+       efficient for partial buffer access.
+
+   * - DWAB (lossy)
+
+     - Lossy compression of RGB data by quantizing discrete cosine
+       transorm (DCT) components, in blocks of 256 scanlines. More
+       efficient space wise and faster to decode full frames than DWAA
+       access.
+
 Luminance/Chroma Images
 =======================