Resampling（重采样）

Zivid 的一个关键优势是固有的 2D 到 3D 映射。点云以有序数组形式返回，并且 RGB 值与其各自的点一一对应。

However, the required resolution of the 3D data is not always the same as the required resolution of the 2D data. For example, one often requires higher resolution 2D than 3D. When you capture a separate 2D image and a 3D point cloud, the 2D image may have a higher resolution than the 3D point cloud. This can be done with the Settings::Sampling::Pixel settings, see Pixel and Pixel（像素）.

To maintain the 1-to-1 correspondence between the 2D and 3D data, the 3D data can be resampled to match the resolution of the 2D data. This can be done with Settings::Processing::Resampling.

重采样可以是上采样或下采样。以下两节将分别讨论这两者。

上采样 

通常用于匹配 2D 分辨率，当 3D 分辨率低于 2D 分辨率时使用。

例子

以下示例展示了如何捕获具有不同分辨率的 2D 和 3D 数据，同时保持 2D 和 3D 数据之间的一一对应关系。

2x2 子采样 3D 和全分辨率 2D

以下图片是使用全分辨率 2D 设置和子采样 3D 设置捕获的。3D 数据进一步进行上采样以匹配 2D 图像的分辨率。

C++

auto settings2D = Zivid::Settings2D{
    Zivid::Settings2D::Acquisitions{ Zivid::Settings2D::Acquisition{} },
    Zivid::Settings2D::Sampling::Pixel::all,
};
auto settings = Zivid::Settings{
    Zivid::Settings::Engine::stripe,
    Zivid::Settings::Acquisitions{ Zivid::Settings::Acquisition{} },
    Zivid::Settings::Sampling::Pixel::blueSubsample2x2,
    Zivid::Settings::Sampling::Color::disabled,
    Zivid::Settings::Processing::Resampling::Mode::upsample2x2,
};

Python

settings_2d = zivid.Settings2D()
settings_2d.acquisitions.append(zivid.Settings2D.Acquisition())
settings_2d.sampling.pixel = zivid.Settings2D.Sampling.Pixel.all
settings = zivid.Settings()
settings.engine = "stripe"
settings.acquisitions.append(zivid.Settings.Acquisition())
settings.sampling.pixel = zivid.Settings.Sampling.Pixel.blueSubsample2x2
settings.sampling.color = zivid.Settings.Sampling.Color.disabled
settings.processing.resampling.mode = zivid.Settings.Processing.Resampling.Mode.upsample2x2

全分辨率 2D

3D 深度图像

3D 点云

（旋转视角）

小心

注意箱子底部和棋盘格之间的点串。这是由于将3D数据进行上采样以匹配2D数据分辨率而产生的伪影。

4x4 子采样 3D 和 2x2 子采样 2D

以下图片是使用 2x2 子采样 2D 设置捕获的。3D 设置是 4x4 子采样，然后进行 2x2 上采样以匹配 2D 图像的分辨率。

C++

auto settings = Zivid::Settings{ Zivid::Settings::Acquisitions{ Zivid::Settings::Acquisition{} },
                                 Zivid::Settings::Color{ Zivid::Settings2D{
                                     Zivid::Settings2D::Acquisitions{ Zivid::Settings2D::Acquisition{} } } } };

auto model = camera.info().model();
switch(model.value())
{
    case Zivid::CameraInfo::Model::ValueType::zividTwo:
    case Zivid::CameraInfo::Model::ValueType::zividTwoL100:
    {
        settings.set(Zivid::Settings::Sampling::Pixel::blueSubsample2x2);
        settings.set(Zivid::Settings::Processing::Resampling::Mode::upsample2x2);
        settings.color().value().set(Zivid::Settings2D::Sampling::Pixel::all);
        break;
    }
    case Zivid::CameraInfo::Model::ValueType::zivid2PlusM130:
    case Zivid::CameraInfo::Model::ValueType::zivid2PlusM60:
    case Zivid::CameraInfo::Model::ValueType::zivid2PlusL110:
    {
        settings.set(Zivid::Settings::Sampling::Pixel::blueSubsample4x4);
        settings.set(Zivid::Settings::Processing::Resampling::Mode::upsample2x2);
        settings.color().value().set(Zivid::Settings2D::Sampling::Pixel::blueSubsample2x2);
        break;
    }
    case Zivid::CameraInfo::Model::ValueType::zivid2PlusMR130:
    case Zivid::CameraInfo::Model::ValueType::zivid2PlusMR60:
    case Zivid::CameraInfo::Model::ValueType::zivid2PlusLR110:
    case Zivid::CameraInfo::Model::ValueType::zivid3XL250:
    {
        settings.set(Zivid::Settings::Sampling::Pixel::by4x4);
        settings.set(Zivid::Settings::Processing::Resampling::Mode::upsample2x2);
        settings.color().value().set(Zivid::Settings2D::Sampling::Pixel::by2x2);
        break;
    }
    case Zivid::CameraInfo::Model::ValueType::zividOnePlusSmall:
    case Zivid::CameraInfo::Model::ValueType::zividOnePlusMedium:
    case Zivid::CameraInfo::Model::ValueType::zividOnePlusLarge:
    {
        throw std::runtime_error("Unsupported camera model '" + model.toString() + "'");
    }
    default: throw std::runtime_error("Unhandled enum value '" + model.toString() + "'");
}

Python

settings = zivid.Settings(
    acquisitions=[zivid.Settings.Acquisition()],
    color=zivid.Settings2D(acquisitions=[zivid.Settings2D.Acquisition()]),
)

model = camera.info.model
if model in {zivid.CameraInfo.Model.zividTwo, zivid.CameraInfo.Model.zividTwoL100}:
    settings.sampling.pixel = zivid.Settings.Sampling.Pixel.blueSubsample2x2
    settings.processing.resampling.mode = zivid.Settings.Processing.Resampling.Mode.upsample2x2
    settings.color.sampling.pixel = zivid.Settings2D.Sampling.Pixel.all
elif model in {
    zivid.CameraInfo.Model.zivid2PlusM130,
    zivid.CameraInfo.Model.zivid2PlusM60,
    zivid.CameraInfo.Model.zivid2PlusL110,
}:
    settings.sampling.pixel = zivid.Settings.Sampling.Pixel.blueSubsample4x4
    settings.processing.resampling.mode = zivid.Settings.Processing.Resampling.Mode.upsample2x2
    settings.color.sampling.pixel = zivid.Settings2D.Sampling.Pixel.blueSubsample2x2
elif model in {
    zivid.CameraInfo.Model.zivid2PlusMR130,
    zivid.CameraInfo.Model.zivid2PlusMR60,
    zivid.CameraInfo.Model.zivid2PlusLR110,
    zivid.CameraInfo.Model.zivid3XL250,
}:
    settings.sampling.pixel = zivid.Settings.Sampling.Pixel.by4x4
    settings.processing.resampling.mode = zivid.Settings.Processing.Resampling.Mode.upsample2x2
    settings.color.sampling.pixel = zivid.Settings2D.Sampling.Pixel.by2x2
else:
    raise ValueError(f"Unsupported camera model '{model}'")