Hi everyone, I hope someone can clarify my issue when it comes to an RGB jpeg2000 image call Using GDALBeginAsyncReader(). I can use this function already for Grayscale images, but Having problems getting RGB colors to work.
In streaming jpeg2000 images (JPIP),How do you properly use GDALBeginAsyncReader() parameters in conjunction with GDALARGetNextUpdatedRegion(). So far, I usually get a AccessViolation which fails on the GDALARGetNextUpdatedRegion() call. That would mean the way I provide the parameter information is not correct. Do I call GDALBeginAsyncReader() three times like RasterIO? One call for Red, one for Blue, and Green? If I am correct, GDALBeginAsyncReader only needs to be called once. This function asks for the BandCount (1 for GrayScale, 3 for RGB) and Bandmap (Where 1 is GrayScale, and when in case for RGB, 1 == Red Band 2 == Blue Band 3 == Green Band). Am I correct so far? For the Length of Buffer where I want to place the bytes, Should I have the parameter as (xSize * GDALGetRasterCount(fileDataset) ) On top of this, can someone give me an example call to GDALBeginAsyncReader() with parameters for an RGB image. Example not exact: Assume: ImageWidth = 800 ImageHeight = 400 BufferXSize = 400 BufferYSize = 400 colorScheme = 3 (For RGB) Bandmap[0] = 1, Bandmap[1] = 2, Bandmap[2] = 3 BYTE* JPIP_Buffer = (BYTE*)CLPMalloc(BufferXSize * BufferYSize * colorScheme) Now, would I call the function as: GDALBeginAsyncReader(fileDataset, 0, 0, //Start at top-left position BufferXSize, BufferYSize, JPIP_Buffer, BufferXSize * colorScheme, BufferYSize, GDT_Byte, colorScheme, Bandmap, 0, 0, 0, 0); How is the image data stored in JPIP_Buffer. Whould it be: 1.rgbrgbrgbrgb 2.rrrrggggbbbb 3.bgrbgrbgrbgr Thanks in advanced!!
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