Raster Mosaic

Introduction

Combine two or more raster datasets into one dataset based on its geographic coordinate system.

e.g.:

Figure 1

Figure 2

Figure 1 shows the raster datasets that have no common parts. Figure 2 shows you how to mosaic the taster datasets that have overlaid parts.

Basic Steps

1. Click Data Processing, Raster Mosaic.
2. The Mosaic dialog box pops up.
3. Add raster datasets.
4. Raster dataset type: Grid and Image. But the two types cannot be mixed.

If you want to change the type, you must delete the added dataset first.

Instruction for Toolbar Button

• Click Add, and select raster datasets.
• Click Remove to remove datasets.
• Click Select All to select all datasets.
• Click Select Inverse.
• Forward the dataset.
• Backward the dataset.
• Top the dataset.
• Bottom the dataset.
• Parameter settings.

Parameter Settings

Raster parameter settings

• Overlay Area Values: Gets cell values, such as elevation, rainfall, etc. There are five approaches:

  • Same as First: The cell values for the first raster dataset.
  • Same as last: The cell values for the last raster dataset.
  • Max of All Datasets: The max cell value of the raster dataset.
  • Min of All Datasets: The min cell value of the raster dataset.
  • Mean of All Datasets: The mean cell value of the raster dataset.

• Format: Sets the pixel type for the result dataset.

  • Same as First: The pixel format for the first raster dataset.
  • Same as Last: The pixel format for the last raster dataset.
  • Highest Precision: The pixel format of the raster dataset that has the highest precision.
  • Lowest Precision: The pixel format of the raster dataset that has the lowest precision.
  • Most Frequent: The pixel format of the raster datasets that have the most frequent.
• Pixel Format: There are bit1, bit4, bit8, bit16, integer, long integer, float, double. See Pixel types of raster dataset.
• NoValue Data: Set a value if the dataset is null.
• Tolerance: Set the tolerance of the no value data.

Image parameter settings

• Overlay Area Values: Gets cell values, including color value or color index. There are two approaches:

  • Same as First: The cell values for the first raster dataset.
  • Same as Last: The cell values for the last raster dataset.
  • Max of All Datasets: Get the max values of R, G, B
  • Min of All Datasets: Get the min values of R, G, B
  • Mean of All Datasets: Get the mean values of R, G, B

• Format: Sets the pixel type for the result dataset. Notes: The pixel formats do not support the single and double float of image dataset mosaic.

  • Same as First: The pixel format for the first image dataset.
  • Same as Last: The pixel format for the last image dataset.
  • Highest Precision: The pixel format of the image dataset that has the highest precision.
  • Lowest Precision: The pixel format of the image dataset that has the highest precision.
  • Most Frequent: The pixel format of the image datasets that have the most frequent.
• Pixel Format: There are Monochrome, 16-color, 256-color, true color, enhanced true color. See Pixel types of image dataset.
• Background: If a cell is the same to this color, it will be treated as background color. In this case, the color will not join to operation.
• Tolerance: Set the tolerance of the background color.

Result Dataset

• Datasource: By default the datasource is the dataset to be mosaicked.
• Dataset: The name of the result dataset.
• Encoding: SGL, DCT, LZW, PNG, Compound. Default is None. See Dataset Compact Encoding.

Encoding for raster dataset:

Original Encoding	Usable Encoding
	1 Bit	4 Bit	Single-byte	Double-byte	Integer	Long integer	Float	Double
NONE	LZW	LZW	LZW, SGL	LZW, SGL	LZW, SGL	NONE	LZW, SGL	LZW, SGL
SGL	LZW	LZW	SGL	SGL	SGL	NONE	SGL	SGL
LZW	LZW	LZW	LZW	LZW	LZW	NONE	LZW	LZW

Encoding for image dataset:

Original Encoding	Usable Encoding
	Monochrome	16-color	256-color	Color	True color	Enhanced color
NONE	LZW, PNG	LZW, PNG	LZW, DCT, PNG, compound	LZW, DCT, compound	LZW, DCT, PNG, compound	LZW, DCT, PNG, compound
LZW	LZW	LZW	LZW	LZW	LZW	LZW
DCT	LZW	LZW	DCT	DCT	DCT	DCT
PNG	PNG	PNG	PNG	DCT	PNG	PNG
Compound	LZW	LZW	Compound	Compound	Compound	Compound

• Create Image Pyramid: To improve the view speed.
• Parameter settings.

Set the extent of the result dataset.

6. Click OK to perform.

Notes

The pixel formats do not support single and double floats of image dataset mosaic.