IWICJpegFrameEncode interface
Exposes methods for writing compressed JPEG scan data directly to the WIC encoder's output stream. Also provides access to the Huffman and quantization tables.
Members
The IWICJpegFrameEncode interface inherits from the IUnknown interface. IWICJpegFrameEncode also has these types of members:
Methods
The IWICJpegFrameEncode interface has these methods.
| Method | Description |
|---|---|
| GetAcHuffmanTable |
Retrieves a copy of the AC Huffman table for the specified scan and table. |
| GetDcHuffmanTable |
Retrieves a copy of the DC Huffman table for the specified scan and table. |
| GetQuantizationTable |
Retrieves a copy of the quantization table. |
| WriteScan |
Writes scan data to a JPEG frame. |
Remarks
Obtain this interface by calling IUnknown::QueryInterface on the Windows-provided IWICBitmapFrameEncoder interface for the JPEG encoder.
The WIC JPEG encoder supports a smaller subset of JPEG features than the decoder does.
- The encoder is limited to a single scan. It does not support encoding images that are multi-scan, either for progressive encoding or planar component data.
- The encoder supports two quantization tables, two AC Huffman tables, and two DC Huffman tables. The luma tables are used for the Y channel and, in the case of YCCK, the black channel. The chroma tables are used for the CbCr channels.
- The encoder supports encoding gray, YCbCr (RGB), and YCCK (CMYK).
- The encoder supports 4 fixed compontent subsampling, 4:2:0, 4:2:2, 4:4:0, and 4:4:4. This subsamples chroma only.
- The encoder does not support restart markers.
Requirements
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Minimum supported client |
Windows 10 [desktop apps only] |
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Minimum supported server |
Windows Server 2016 [desktop apps only] |
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Header |
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IDL |
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Library |
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DLL |
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