Changes between Version 1 and Version 2 of FDORfc65
- Timestamp:
- 10/12/12 12:54:23 (12 years ago)
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FDORfc65
v1 v2 30 30 == Proposed Solution == 31 31 32 A new class FdoRfpStreamReaderByTileResample is introduced to implement resampling behaviour. It maintains a member instance of the existingFdoRfpStreamReaderByTile to perform the reading and resampling from the GDAL library. The member reader samples at 2x the required pixel density. This data is then downsampled to the required pixel density using one of resampling methods supported by GDAL warp:32 A new class !FdoRfpStreamReaderByTileResample is introduced to implement resampling behaviour. It maintains a member instance of the existing !FdoRfpStreamReaderByTile to perform the reading and resampling from the GDAL library. The member reader samples at 2x the required pixel density. This data is then downsampled to the required pixel density using one of resampling methods supported by GDAL warp: 33 33 * Bilinear - Bilinear resampling 34 34 * Cubic - Cubic resampling 35 * CubicSpline - Cubic spline resampling35 * !CubicSpline - Cubic spline resampling 36 36 * Lanczos - Lanczos windowed sinc resampling 37 37 38 The resampling method is specified by a new "ResamplingMethod" parameter in the connection string for the provider. 38 The resampling method is specified by a new "!ResamplingMethod" parameter in the connection string for the provider. The parameter values are case insensitive. 39 39 40 {{{ 40 41 m_connection->SetConnectionString(L"DefaultRasterFileLocation=../../TestData/pci_eg/acea.tif;ResamplingMethod=bilinear"); … … 43 44 The internal reader uses a memory buffer to supply the GDAL warp operation with data. This eliminates any performance issues caused by writing temporary data to disk. 44 45 45 The FdoRfpStreamReaderByTileResample reader automatically upgrades all bit depths and color to 32 bit RGBA. A 32 bit color space is generally required to accurately display the blended pixels resulting from the resampling.46 The !FdoRfpStreamReaderByTileResample reader automatically upgrades all bit depths and color to 32 bit RGBA. A 32 bit color space is generally required to accurately display the blended pixels resulting from the resampling. 46 47 47 48 == Implications ==