Hi, My gdal is 1.8.0.I use GDALDataset::RasterIO to read from a img file .The file size is 30G bytes ,three bands,data type is GDT_Byte and have 8 overviews.When overview is used or there is no need to resample ,it`s fast.But when resample is needed,i found gdal copy pixel data 1 byte by 1 byte in fllow codes: memcpy( ((GByte *) pData) + iBandBufOffset, pabySrcBlock + iSrcOffset, nBandDataSize ); Codes is in rasterio.cpp at 2150 lines. My question is why copy 1 byte at one time.and how to improve it.. Thanks.
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