本文整理汇总了C++中GDALRasterBand::GetBand方法的典型用法代码示例。如果您正苦于以下问题：C++ GDALRasterBand::GetBand方法的具体用法？C++ GDALRasterBand::GetBand怎么用？C++ GDALRasterBand::GetBand使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类GDALRasterBand的用法示例。
在下文中一共展示了GDALRasterBand::GetBand方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: get_feature
//.........这里部分代码省略.........
GDALColorTable *color_table = red->GetColorTable();
bool has_nodata = nodata_value_ || raster_has_nodata;
// we can deduce the alpha channel from nodata in the Byte case
// by reusing the reading of R,G,B bands directly
if (has_nodata && !color_table && red->GetRasterDataType() == GDT_Byte)
{
double apply_nodata = nodata_value_ ? *nodata_value_ : raster_nodata;
// read the data in and create an alpha channel from the nodata values
// TODO - we assume here the nodata value for the red band applies to all bands
// more details about this at http://trac.osgeo.org/gdal/ticket/2734
float* imageData = (float*)image.bytes();
raster_io_error = red->RasterIO(GF_Read, x_off, y_off, width, height,
imageData, image.width(), image.height(),
GDT_Float32, 0, 0);
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
int len = image.width() * image.height();
for (int i = 0; i < len; ++i)
{
if (std::fabs(apply_nodata - imageData[i]) < nodata_tolerance_)
{
*reinterpret_cast<unsigned *>(&imageData[i]) = 0;
}
else
{
*reinterpret_cast<unsigned *>(&imageData[i]) = 0xFFFFFFFF;
}
}
}
/* Use dataset RasterIO in priority in 99.9% of the cases */
if( red->GetBand() == 1 && green->GetBand() == 2 && blue->GetBand() == 3 )
{
int nBandsToRead = 3;
if( alpha != NULL && alpha->GetBand() == 4 && !raster_has_nodata )
{
nBandsToRead = 4;
alpha = NULL; // to avoid reading it again afterwards
}
raster_io_error = dataset_.RasterIO(GF_Read, x_off, y_off, width, height,
image.bytes(),
image.width(), image.height(), GDT_Byte,
nBandsToRead, NULL,
4, 4 * image.width(), 1);
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
}
else
{
raster_io_error = red->RasterIO(GF_Read, x_off, y_off, width, height, image.bytes() + 0,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
raster_io_error = green->RasterIO(GF_Read, x_off, y_off, width, height, image.bytes() + 1,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
raster_io_error = blue->RasterIO(GF_Read, x_off, y_off, width, height, image.bytes() + 2,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());