IDAHO Image Metadata Files Overview
These are the metadata files associated with IDAHO images. Not all metadata files are available for all IDAHO images. The metadata files available for an IDAHO image depends on the data source of the image. See "profile" information below.
This is the list of metadata files for an image. Click the name to see an example and metadata descriptions.
| File Name | Description |
|---|---|
| image.json | Core image metadata files |
| rrds.json | A listing of Reduced Resolution Datasets available for the IDAHO image |
| georeferencing.json | Georeferencing information for the IDAHO Image |
| rpcs.json | DigitalGlobe RPC sensor model parameters |
| native_warp_spec.json | Wrap grid for orthorectifying the IDAHO image |
| histogram.json | Histogram for the IDAHO image |
Profiles
IDAHO images fit into one of the profiles listed here. The profile indicates which types of metadata are available for that image.
| Profile Name | Source Image | Metadata Types |
|---|---|---|
| dg_1b | DigitalGlobe level 1B image | image.json, rpcs.json file, native_warp_spec.json file, histogram.json file, 5 rrd levels, DG product metadata (.IMD, .XML, etc) |
| georectified_image | geoferenced image (as opposed to a raw or otherwise unrectified image) | image.json, georeferencing.json |
vendor Dataset Identifier
For DigitalGlobe images the vendorDatasetIdentifier is formatted; "{PRODUCT_LEVEL}:{PRODUCT_ORDER_ID}:{CAT_ID}:{PRODUCT_CAT_ID}". This identifier is useful as a means to reference back to other vendor-supplied catalogs.
Example vendorDatasetIdentifier: "LV1B:053864309030_01_p001:1030010037A14B00:2020010129405000"
image.json
This file contains the core image metadata, such as number of rows/cols, data types, and other common values used to select the image. The image.json file is required for all IDAHO images.
Example image.json file
{
"imageId": "bde4b243-a647-4699-807b-6abe0d6fcd12",
"version": "1.0",
"profileName": "dg_1b",
"tileBucketName": "idaho-demo-oregon",
"tilePartition": "0000",
"nativeTileFileFormat": "TIF",
"tileXOffset": 0,
"tileYOffset": 0,
"numXTiles": 35,
"numYTiles": 27,
"tileXSize": 256,
"tileYSize": 256,
"numBands": 8,
"dataType": "UNSIGNED_SHORT",
"imageHeight": 6773,
"imageWidth": 8820,
"sensorPlatformName": "WV02",
"sensorName": "8-band (Coastal, Blue, Green, Yellow, Red, Red-edge, NIR1, NIR2) Multispectral",
"vendorName": "DigitalGlobe, Inc.",
"vendorDatasetIdentifier": "LV1B:053864309030_01_P001:1030010037A14B00:2020010129405000",
"acquisitionDate": "2014-09-09T06:50:26.467Z",
"colorInterpretation": "WORLDVIEW_8_BAND",
"imageBoundsWGS84": "POLYGON ((58.71332241 25.66113728, 58.91368505 25.63821421, 58.91276839 25.50867659, 58.71402146 25.52907957, 58.71332241 25.66113728))",
"groundSampleDistanceMeters": 2.229
}Contents of image.json file
| Element | Type | Description |
|---|---|---|
| imageId | string | The IDAHO ID |
| version | string | the IDAHO specification version |
| profileName | string | the profile that this IDAHO image conforms to. This can be used to know what files will exist for the image |
| tileBucketName | string | the bucket where the IDAHO images' tiles exist |
| tilePartition | string | the partition where the IDAHO images' tiles exist. This value is used in deriving each tile's hash prefix |
| nativeTileFileFormat | string | the image file format for the IDAHO images' tiles. Can be "PNG" or "TIF" |
| tileXOffset | number | the X offset for the first upper left pixel of the IDAHO image |
| tileYOffset | number | the Y offset for the first upper left pixel of the IDAHO image |
| numXTiles | number | the number of tiles across the X direction of the IDAHO image |
| numYTiles | number | the number of tiles in the Y direction of the IDAHO image |
| tileXSize | number | the number of pixels across the X direction in the IDAHO image tiles |
| tileYSize | number | the number of pixels in the Y direction in the IDAHO image tiles |
| numBands | number | the number of image bands in the IDAHO image tiles |
| dataType | string | the data type of the pixeles in the IDAHO image tiles |
| imageHeight | number | The number of pixels in the Y dimension of the IDAHO image |
| imageWidth | number | The number of pixels in the X dimension of the IDAHO image |
| sensorPlatformName | string | the name of the sensor platform (satellite) that captured the image |
| sensorName | string | the name of the sensor that captured the image |
| vendorName | string | the name of the company that produced the image |
| vendorDatasetIdentifier | string | the vendor specific ID of the image |
| acquisitionDate | string | The date time when the image was captured |
| colorInterpretation | string | the name that indicates the band order of the image |
| imageBoundsWGS84 | string | the WKT geographical bounds of the image |
| groundSampleDistanceMeters | number | the approximate size in meters of one pixel |
rrds.json
This file contains a list of Reduced Resolution Datasets (RRDs) of the IDAHO image. RRDs have lower spatial resolution and therefore are smaller and quicker to load then the full dataset. They are used for quickly browsing over the imagery.
Example rrds.json file
{
"reducedResolutionDataset": [{
"sourceImage": "bde4b243-a647-4699-807b-6abe0d6fcd12",
"targetImage": "f53538cc-58c0-4b4d-bb09-150f4ae4567d",
"inverseScaleFactor": 2.0
}, {
"sourceImage": "f53538cc-58c0-4b4d-bb09-150f4ae4567d",
"targetImage": "a35a0e9f-a07e-4df8-a72d-3c0e9bc9a315",
"inverseScaleFactor": 2.0
}, {
"sourceImage": "a35a0e9f-a07e-4df8-a72d-3c0e9bc9a315",
"targetImage": "7a315eb5-e9b5-4f89-bb0b-5abcbf43aec1",
"inverseScaleFactor": 2.0
}, {
"sourceImage": "7a315eb5-e9b5-4f89-bb0b-5abcbf43aec1",
"targetImage": "5df79860-90d3-4810-ade3-79ad0b063769",
"inverseScaleFactor": 2.0
}, {
"sourceImage": "5df79860-90d3-4810-ade3-79ad0b063769",
"targetImage": "d4adebe2-ee6b-401b-9d33-d2b9dfdbeaa2",
"inverseScaleFactor": 2.0
}]
}Contents of rrds.json file
The rrds.json file contains a reducedResolutionDataset. Each rrd listed in the dataset consists of the following values:
| Value | Type | Description |
|---|---|---|
| sourceImage | string | the IDAHO ID of the RRD source image |
| targetImage | string | the IDAHO ID of the RRD image |
| inverseScaleFactor | number | the scale factor used to produce the RRD |
Location
RRDs will be located in the same S3 bucket as the source image.
georeferencing.json
This file contains the geographical referencing for the IDAHO image. The georeferencing metadata contains the parameters to build the affine transformation needed to georeference the image. IDAHO images with a profile of "georectified_image" will include the georeferencing.json file.
Example georeferencing.json
{
"spatialReferenceSystemCode": "EPSG:4326",
"scaleX": 4.48787913602941E-6,
"scaleY": -4.48787913602941E-6,
"translateX": -108.63281025606044,
"translateY": 46.66991963106043,
"shearX": 0.0,
"shearY": 0.0
}Contents georeferencing.json
| Value | Type | Description |
|---|---|---|
| spatialReferenceSystemCode | string | the system:value that specifies the spatial reference system |
| scaleX | number | specifies the scale factor along the x axis |
| scaleY | number | specifies the scale factor along the x axis |
| translateX | number | specifies the displacement along the x axis |
| translateY | number | specifies the displacement along the y axis |
| shearX | number | specifies the shear factor along the x axis |
| shearY | number | specifies the shear factor along the y axis |
rpcs.json
This file contains the RPC information, which can be used to rectify the image. This is a mathematical mapping from object space coordinates to image space coordinates.
The values in the rpcs.json are the same as the DigitalGlobe RPC00B file. Please refer to the DigitalGlobe Imagery Support Data Documentation for details .
Example rpcs.json file
{
"spatialReferenceSystem": "EPSG:4326",
"upperLeftCorner": {
"x": 58.71332241,
"y": 25.66113728
},
"upperRightCorner": {
"x": 58.91368505,
"y": 25.63821421
},
"lowerRightCorner": {
"x": 58.91276839,
"y": 25.50867659
},
"lowerLeftCorner": {
"x": 58.71402146,
"y": 25.52907957
},
"gsd": 2.002335609054977E-5,
"lineOffset": 3386.0,
"sampleOffset": 4409.0,
"latOffset": 25.5849,
"lonOffset": 58.8134,
"heightOffset": 11.0,
"lineScale": 3386.0,
"sampleScale": 4410.0,
"latScale": 0.0778,
"lonScale": 0.1023,
"heightScale": 501.0,
"lineNumCoefs": [-0.01247868, -0.1699803, -1.193688, -0.01892405, -0.002366152, -1.213828E-4, -2.886388E-4, -7.654795E-4, 0.009362892, 5.499658E-6, 3.702268E-5, 1.141359E-4, 9.568873E-4, 1.545527E-4, 8.740161E-4, 0.003490795, 0.001083495, 1.617478E-5, 9.24004E-5, 1.716484E-5],
"lineDenCoefs": [1.0, -0.005079786, -0.003750422, -6.034228E-4, 0.001396144, 1.490369E-7, 1.645065E-4, -5.660189E-4, 0.003022191, -9.087502E-4, -1.39079E-5, 3.636066E-6, -5.448129E-4, 7.65754E-6, -6.239931E-5, -0.001555249, -2.609868E-6, 8.087889E-8, -5.860598E-5, 9.089406E-7],
"sampleNumCoefs": [-0.006631238, 1.025698, 4.836109E-5, -0.02188833, -0.002148, 1.639059E-4, 9.741724E-5, 0.005816214, -3.656549E-5, -3.09791E-6, -2.092807E-6, 1.607785E-5, -4.504992E-5, -5.230266E-6, -4.981685E-5, 1.146771E-4, 2.640311E-7, 1.915519E-6, 6.6408E-6, 1.156241E-7],
"sampleDenCoefs": [1.0, 8.39283E-4, 0.00220421, -3.132964E-4, 3.887315E-5, -1.358456E-6, 1.434978E-6, 6.141316E-6, 4.193624E-5, -5.176659E-6, 1.161258E-7, 6.575535E-8, -1.242692E-6, 2.477381E-8, 7.813111E-7, -9.281618E-6, -1.879341E-8, 0.0, -1.391419E-7, 0.0],
"postScaleFactorX": 1.0,
"postScaleFactorY": 1.0
}native_warp_spec.json
The native_warp_spec.json file contains the warp grid specification for the IDAHO image. The warp grid can be used to orthorectify the IDAHO image.
Example native_warp_spec.json file
{
"numXCells": 201,
"numYCells": 153,
"targetGeoTransform": {
"scaleX": 2.00234e-05,
"scaleY": -2.00234e-05,
"shearX": 0,
"shearY": 0,
"spatialReferenceSystemCode": "EPSG:4326",
"translateX": 58.7133,
"translateY": 25.6611
},
"warpPositions": [-4.91524, -3.30698, 38.9481, -8.94853, 82.0331, -15.1185, 125.709, -20.8939, 169.194 (this example list is truncated due to length)
"xStart": 0,
"xStep": 50,
"yStart": 0,
"yStep": 50
}Contents of native_warp_spec.json file
| Value | Type | Description |
|---|---|---|
| numXCells | number | number of cells (2D points) in the X direction |
| numYCells | number | number of cells (2D points) in the Y direction |
| targetGeoTransform (values below indicated by "*") | targetGeoTransform (values below indicated by "*") | Target output affine in the given spatialReferenceSystemCode |
| *spatialReferenceSystemCode | string | the system:value that specifies the spatial reference system |
| * scaleX | number | specifies the scale factor along the x axis |
| * scaleY | number | specifies the scale factor along the x axis |
| * translateX | number | specifies the displacement along the x axis |
| * translateY | number | specifies the displacement along the y axis |
| * shearX | number | specifies the shear factor along the x axis |
| * shearY | number | specifies the shear factor along the y axis |
| xStart | number | the X position of the upper left corner of the warp grid |
| yStart | number | the Y postion of the upper left corner of the warp grid |
| xStep | number | the X spacing in output pixels between the cells of the warp grid |
| yStep | number | the Y spacing in output pixels between the cells of the warp grid |
| warpPositions | list | list, a list of cells given in x1,y1,x2,y2,x3,y3,... order. The values represent input pixel row/col. |
histogram.json
This file contains the histogram for the IDAHO image.
Note: Due to the length of each list in the histogram, an image of an example is being used here instead of real file contents.
Contents of histogram.json file
| Value | Type | Description |
|---|---|---|
| histograms (list values starred below) | list | list of name/value pairs |
| *name | string | the name of the band |
| * histogram | list | a list of counts, one for each bin |
| numBins | list | list of number of bins, there will be one value for each band |
| numBands | number | number of bands in the histogram |