Multi Source Schema

A multi-source tile source is used to composite multiple other sources into a single conceptual tile source. It is specified by a yaml or json file that conforms to the appropriate schema.

Examples

All of the examples presented here are in yaml; json works just as well.

Multi Z-position

For example, if you have a set of individual files that you wish to treat as multiple z slices in a single file, you can do something like:

---
sources:
  - path: ./test_orient1.tif
    z: 0
  - path: ./test_orient2.tif
    z: 1
  - path: ./test_orient3.tif
    z: 2
  - path: ./test_orient4.tif
    z: 3
  - path: ./test_orient5.tif
    z: 4
  - path: ./test_orient6.tif
    z: 5
  - path: ./test_orient7.tif
    z: 6
  - path: ./test_orient8.tif
    z: 7

Here, each of the files is explicitly listed with a specific z value. Since these files are ordered, this could equivalently be done in a simpler manner using a pathPattern, which is a regular expression that can match multiple files.

---
sources:
  - path: .
    pathPattern: 'test_orient[1-8]\.tif'
    zStep: 1

Since the z value will default to 0, this works. The files are sorted in C-sort order (lexically using the ASCII or UTF code points). This sorting will break down if you have files with variable length numbers (e.g., file10.tif will appear before file9.tiff. You can instead assign values from the file name using named expressions:

---
sources:
  - path: .
    pathPattern: 'test_orient(?P<z1>[1-8])\.tif'

Note that the name in the expression (z1 in this example) is the name of the value in the schema. If a 1 is added, then it is assumed to be 1-based indexed. Without the 1, it is assumed to be zero-indexed.

Composite To A Single Frame

Multiple sources can be made to appear as a single frame. For instance:

---
width: 360
height: 360
sources:
  - path: ./test_orient1.tif
    position:
      x: 0
      y: 0
  - path: ./test_orient2.tif
    position:
      x: 180
      y: 0
  - path: ./test_orient3.tif
    position:
      x: 0
      y: 180
  - path: ./test_orient4.tif
    position:
      x: 180
      y: 180

Here, the total width and height of the final image is specified, along with the upper-left position of each image in the frame.

Composite With Scaling

Transforms can be applied to scale the individual sources:

---
width: 720
height: 720
sources:
  - path: ./test_orient1.tif
    position:
      scale: 2
  - path: ./test_orient2.tif
    position:
      scale: 2
      x: 360
  - path: ./test_orient3.tif
    position:
      scale: 2
      y: 360
  - path: ./test_orient4.tif
    position:
      scale: 360
      x: 180
      y: 180

Note that the zero values from the previous example have been omitted as they are unnecessary.

Full Schema

The full schema (jsonschema Draft6 standard) can be obtained by referencing the Python at large_image_source_multi.MultiSourceSchema.

This returns the following:

{
  "$schema": "http://json-schema.org/schema#",
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "name": {
      "type": "string"
    },
    "description": {
      "type": "string"
    },
    "width": {
      "type": "integer",
      "exclusiveMinimum": 0
    },
    "height": {
      "type": "integer",
      "exclusiveMinimum": 0
    },
    "tileWidth": {
      "type": "integer",
      "exclusiveMinimum": 0
    },
    "tileHeight": {
      "type": "integer",
      "exclusiveMinimum": 0
    },
    "channels": {
      "description": "A list of channel names",
      "type": "array",
      "items": {
        "type": "string"
      },
      "minItems": 1
    },
    "scale": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "mm_x": {
          "type": "number",
          "exclusiveMinimum": 0
        },
        "mm_y": {
          "type": "number",
          "exclusiveMinimum": 0
        },
        "magnification": {
          "type": "integer",
          "exclusiveMinimum": 0
        }
      }
    },
    "backgroundColor": {
      "description": "A list of background color values in the same scale and band order as the first tile source",
      "type": "array",
      "items": {
        "type": "number"
      }
    },
    "basePath": {
      "decription": "A relative path that is used as a base for all paths in sources.  Defaults to the directory of the main file.",
      "type": "string"
    },
    "uniformSources": {
      "description": "If true and the first two sources are similar in frame layout and size, assume all sources are so similar",
      "type": "boolean"
    },
    "sources": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": false,
        "properties": {
          "name": {
            "type": "string"
          },
          "description": {
            "type": "string"
          },
          "path": {
            "decription": "The relative path, including file name if pathPattern is not specified.  The relative path excluding file name if pathPattern is specified.  Or, girder://id for Girder sources.  If a specific tile source is specified that does not need an actual path, the special value of `__none__` can be used to bypass checking for an actual file.",
            "type": "string"
          },
          "pathPattern": {
            "description": "If specified, file names in the path are matched to this regular expression, sorted in C-sort order.  This can populate other properties via named expressions, e.g., base_(?<xy>\\d+).png.  Add 1 to the name for 1-based numerical values.",
            "type": "string"
          },
          "sourceName": {
            "description": "Require a specific source by name.  This is one of the large_image source names (e.g., this one is \"multi\".",
            "type": "string"
          },
          "frame": {
            "description": "Base value for all frames; only use this if the data does not conceptually have z, t, xy, or c arrangement.",
            "type": "integer",
            "minimum": 0
          },
          "z": {
            "description": "Base value for all frames",
            "type": "integer",
            "minimum": 0
          },
          "t": {
            "description": "Base value for all frames",
            "type": "integer",
            "minimum": 0
          },
          "xy": {
            "description": "Base value for all frames",
            "type": "integer",
            "minimum": 0
          },
          "c": {
            "description": "Base value for all frames",
            "type": "integer",
            "minimum": 0
          },
          "zValues": {
            "description": "The numerical z position of the different z indices of the source.  If only one value is specified, other indices are shifted based on the source.  If fewer values are given than z indices, the last two value given imply a stride for the remainder.",
            "type": "array",
            "items": {
              "type": "number"
            },
            "minItems": 1
          },
          "tValues": {
            "description": "The numerical t position of the different t indices of the source.  If only one value is specified, other indices are shifted based on the source.  If fewer values are given than t indices, the last two value given imply a stride for the remainder.",
            "type": "array",
            "items": {
              "type": "number"
            },
            "minItems": 1
          },
          "xyValues": {
            "description": "The numerical zy position of the different zy indices of the source.  If only one value is specified, other indices are shifted based on the source.  If fewer values are given than zy indices, the last two value given imply a stride for the remainder.",
            "type": "array",
            "items": {
              "type": "number"
            },
            "minItems": 1
          },
          "cValues": {
            "description": "The numerical c position of the different c indices of the source.  If only one value is specified, other indices are shifted based on the source.  If fewer values are given than c indices, the last two value given imply a stride for the remainder.",
            "type": "array",
            "items": {
              "type": "number"
            },
            "minItems": 1
          },
          "frameValues": {
            "description": "The numerical frame position of the different frame indices of the source.  If only one value is specified, other indices are shifted based on the source.  If fewer values are given than frame indices, the last two value given imply a stride for the remainder.",
            "type": "array",
            "items": {
              "type": "number"
            },
            "minItems": 1
          },
          "channel": {
            "description": "A channel name to correspond with the main image.  Ignored if c, cValues, or channels is specified.",
            "type": "string"
          },
          "channels": {
            "description": "A list of channel names used to correspond channels in this source with the main image.  Ignored if c or cValues is specified.",
            "type": "array",
            "items": {
              "type": "string"
            },
            "minItems": 1
          },
          "zStep": {
            "description": "Step value for multiple files included via pathPattern.  Applies to z or zValues",
            "type": "integer",
            "exclusiveMinimum": 0
          },
          "tStep": {
            "description": "Step value for multiple files included via pathPattern.  Applies to t or tValues",
            "type": "integer",
            "exclusiveMinimum": 0
          },
          "xyStep": {
            "description": "Step value for multiple files included via pathPattern.  Applies to x or xyValues",
            "type": "integer",
            "exclusiveMinimum": 0
          },
          "xStep": {
            "description": "Step value for multiple files included via pathPattern.  Applies to c or cValues",
            "type": "integer",
            "exclusiveMinimum": 0
          },
          "position": {
            "type": "object",
            "additionalProperties": false,
            "description": "The image can be translated with x, y offset, apply an affine transform, and scaled.  If only part of the source is desired, a crop can be applied before the transformation.",
            "properties": {
              "x": {
                "type": "number"
              },
              "y": {
                "type": "number"
              },
              "crop": {
                "description": "Crop the source before applying a position transform",
                "type": "object",
                "additionalProperties": false,
                "properties": {
                  "left": {
                    "type": "integer"
                  },
                  "top": {
                    "type": "integer"
                  },
                  "right": {
                    "type": "integer"
                  },
                  "bottom": {
                    "type": "integer"
                  }
                }
              },
              "scale": {
                "description": "Values less than 1 will downsample the source.  Values greater than 1 will upsample it.",
                "type": "number",
                "exclusiveMinimum": 0
              },
              "s11": {
                "type": "number"
              },
              "s12": {
                "type": "number"
              },
              "s21": {
                "type": "number"
              },
              "s22": {
                "type": "number"
              }
            }
          },
          "frames": {
            "description": "List of frames to use from source",
            "type": "array",
            "items": {
              "type": "integer"
            }
          },
          "style": {
            "type": "object"
          },
          "params": {
            "description": "Additional parameters to pass to the base tile source",
            "type": "object"
          }
        },
        "required": [
          "path"
        ]
      }
    }
  },
  "required": [
    "sources"
  ]
}