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Planimetric Orthophotos

Planimetric Orthophotos

Owned by Omar Lamrani
Last updated: Mar 06, 2025 by Reza Mahmoudi Kuohi
3 min read

Menu: Analyze / Planimetric orthophotos

Version française

The Planimetric Orthophoto tool generates high-resolution orthophotos from the point cloud. Users can create either a single image or a mosaic of multiple images. The orthophotos are rendered from an orthogonal top view, with a customizable pixel size and background transparency.

1. Pixel Value Settings

The value assigned to each pixel depends on the selected display mode:

✔ Intensity Mode

  • Displays the intensity value of the last point found in each pixel.

  • Iterations: Fills empty pixels when at least two neighboring pixels contain a value.

  • Auto Adjust: Recalibrates intensity brightness across all tiles for consistency.

  • Background: Always white.

✔ RGB Mode

  • Displays the RGB value of the last point found in each pixel.

  • Opacity: Controls transparency (0% = fully transparent, 100% = fully opaque).

    • 100% opacity → Background is white.

    • 0% opacity → Background is fully transparent.

✔ By Color Mode

  • Displays a fixed color for any pixel containing a point.

  • Empty pixels are automatically transparent.

  • Opacity: Affects only colored pixels (0% = fully transparent, 100% = fully opaque).

2. Defining the Orthophoto Area

The Bounding Box determines the center point for a single orthophoto or the extent of a mosaic.

✔ By Mosaic (Multiple Images)

  • Creates tiled orthophotos based on the specified image resolution.

  • The user can select:

    • Entire Project – Uses the full extent of the VisionLidar project.

    • Specific Surface – Uses any existing surface in the Explorer → Objects tab.

  • Tile Naming: Each tile is labeled as X_Y, where:

    • X = Column number.

    • Y = Row number.

  • Empty tiles (without points) are not generated.

  • Set Extent: Adjusts the total image size to match the full mosaic area.

✔ Centered on a Point (Single Image)

  • The user must select a center point in the point cloud or enter coordinates.

  • Generates one orthophoto at the requested resolution, centered on the selected point.

3. Image Resolution & Pixel Settings

✔ Units of Measurement

  • Defines the total image size (X & Y) in project units.

  • If Bounding Box is used:

    • Single Image → Represents the total extent of the image.

    • Mosaic → Represents the combined extent of all tiles.

  • When modifying pixel count, this value is automatically updated.

✔ Pixels

  • Sets the number of pixels (X & Y) in each image.

  • If Bounding Box is used:

    • Represents the size of a single image.

    • Automatically updates if Units of Measurement are changed.

✔ Pixel Size

  • Defines the physical size of each pixel in project units.

  • Set Extent: Uses this value to calculate the total image area.

4. Elevation Filtering

The Elevation setting acts as a filter for orthophoto generation:
✔ If using Entire Project → Z-values represent the height of each point in the cloud.
✔ If using a Selected Surface → Elevation is relative to that surface.

📌 Example Use Case:

  • Generate only ground points or images within a specific height range from the ground.

5. Generating & Saving Orthophotos

1️⃣ Press “OK” to generate the orthophoto.
2️⃣ If Mosaic Mode is selected, a message will display the max number of tiles that can be generated.
3️⃣ Choose a save location for the images.
4️⃣ File Naming (for mosaics):

  • Each image name is followed by X_Y (column & row number).
    5️⃣ File Format:

  • TIFF (.tiff) – Includes georeference metadata in the file header.

  • Can be renamed to .tif for compatibility with other software.

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