An Introduction to Batch Transformations

The following workflow uses the Black Mountain.gmw file that was saved at the end of the Accessing Online Data topic.

In this lesson, we will begin our introduction to raster data by looking at the structure and characteristics of the data itself before exploring some of the tools within Global Mapper that are used when working with raster layers.

The resolution of a raster layer is determined by the pixel size. Larger pixels (left) will show less detail but will result in a relatively smaller file. Conversely, smaller pixels (right) will allow more detail to be seen in the image but, because more pixels are required to cover a defined area, the file size will be much larger.

Global Mapper’s raster management tools include:

Feature Info Tool
While normally used to display information about a selected vector feature, the Feature Info tool can also display information about a selected pixel in a raster layer.

Raster Options
Accessed from the Control Center, the raster version of this dialog box offers numerous tools and settings to determine the visual characteristics of the selected layer or layers.

Layer Metadata
Also accessible in the Control Center, the Metadata window provides detailed information about the contents of a layer. Use in the context of raster data, this information includes the pixel size or resolution of the data, which determines how much detail can be seen.

Image Swipe Tool
This simple tool is used to pull back a selected raster layer to reveal the layer below. It is especially useful when conducting a visual comparison between overlapping imagery layers.

Using the Black Mountain workspace, follow along as the instructor explores the use of these tools with some raster layers.

As we delve deeper into Global Mapper’s raster processing functionality, we will explore some of the basic image editing capabilities.

  • Raster data is comprised of an array of pixels, each of which contains measured values, with color values being the most commonly used.
  • Similar to working with vector data, the Feature Info tool can be used to access information about an individual pixel.
  • The Metadata dialog box offers detailed information about the characteristics of a layer.
  • Click here for more information on displaying metadata for a raster layer.

Click on the Mark Complete or Next Topic button to learn more about Adjusting the Display of Raster Layers in Global Mapper.