ImageWriter
Properties
| Property | Characteristic | Dimension | Description |
|---|---|---|---|
| PixelType | compulsory, user-defined, default: float |
0 | The data type of the image pixels to be written. For RGB or multi-band (vector) images, PixelType denotes the data type of the individual image bands, i.e. pixel components. |
| NumDimensions | compulsory, user-defined, default: 2 |
0 | The number of dimensions of the image to be written. LUMASS currently only supports writing 3D images as (into) NetCDF (*.nc) files. |
| NumBands | compulsory, user-defined, default: 1 |
0 | The number of bands of the image to be written. This parameter is required to determine the pixel type of the output image, i.e. scalar (=1), RGB (=3 and RGBMode=True), and multi-band (vector) for all other values. |
| FileNames | compulsory, user-defined, default: empty |
1 | Absolute path(s) to the image(s) to be written; uses forward slash ‘/’ as path separator |
| InputTables | optional, user-defined, default: empty |
1 | List of component output specifications (e.g. TableReader:0) referring to tables to be written into the specified images (FileNames). |
| RGBMode | compulsory, user-defined, default: False |
0 | If this parameter is selected, i.e. RGBMode=True, and NumBands=3, then LUMASS writes an RGB image. |
| WriteImage | compulsory, user-defined, default: True |
0 | When selected, i.e. True, the image(s) is (are) written or updated. When deselected, i.e. False, the image(s) is (are) not written or updated. |
| WriteTable | compulsory, user-defined, default: True |
0 | When selected and a raster attribute table is provided as part of the input image or specified by the InputTables parameter, the raster attritubte table(s) are written into the corresponding image. |
| StreamingMethod | compulsory, user-defined, default: STRIPPED |
0 | Specifies the streaming method to be applied for sequential image processing by the processing-pipeline. If NO_STREAMING is selected, no sequential image processing is applied by this processing pieline. |
| PipelineMemoryFootprint | compulsory, user-defined, default: 512 |
0 | The maximum amount of main memory in megabyte available to this processing pipeline. Note that this value is only an estimation and the actual memory usage may differ from the specified value. |
| PyramidResamplingType | compulsory, user-defined, default: NEAREST |
0 | The resampling algorithm to be used for generating image pyramids for fast display with LUMASS or GIS-type applications. |
Supported Image & Pipeline Features
| Characteristic | Details | Comments |
|---|---|---|
| Image dimensions | 1D, 2D, 3D | |
| Multi-band images | yes | |
| Pipeline role | sink | |
| Sequential processing | yes | |
| Parallel processing | no | |
| Number of inputs | 1..multiple | provided by a single input component |
Overview
The ImageWriter writes images and/or their associated raster attribute tables (RAT) to disk (WriteImage, WriteTable). However, ImageWriter can only write RAT into the specified image file. If you want to write a stand-alone (SQLite-based) table as RAT into the specified image file, please use the TableFileNames property to specify the SQLite database filename.
To create SQLite-based RAT (*.ldb), please refer to the SummarizeZones component. To create stand-alone SQLite-based tables, please refer to the TableReader or the ParameterTable component.
Please refer to the ImageReader component reference for supported image formats and filenames.
Note: If you’re working with large images, i.e. > 2 GiB, we recommend the KEA image format. It keeps image sizes small and also supports RAT for large images!
Sequential Processing and Memory Footprint
Since the ImageWriter is a sink component, it sits at the bottom (downstream) end of a processing pipeline. It enables the sequential processing (StreamingMethod) of large images as chunks of image tiles (TILED) or as chunks of rows (STRIPPED). The approximate maximum memory footprint of a pipeline can be configured with the PipelineMemoryFootprint property.
Image Pyramids
To speed up display in LUMASS or GIS, e.g. QGIS, the ImageWriter automatically creates iamge pyramids. The resampling type used to create image pyramids can be configured using the PyramidResamplingType property. When writing into an image cube that is supposed to be extended further by subsequent write operations, set the PyramidResamplingType to NONE to prevent premature image pyramid generation.
Writing Multiple Images
While this writer can only be connected to one input component, it can write multiple images at a time (cf. Multiple Inputs and Outputs if the input component produces multiple output images (e.g. MapAlgebra or BMIModel). It writes only as many output images as filenames are provided. The order of filenames should reflect the order of Inputs configured for the writer. Images provided in excess of the number of filenames specified, are ignored.
Important: Because FileNames is a 1D property, you can only specify a set of filenames for a single iteration when writing multiple images. However, by using parameter expressions, you can still dynamically change the set of filenames to support multiple iterations.