Difference between revisions of "Background Image"
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Anatrancoso (talk | contribs) (New page: * Import ESRI geo-referenced image ESRI geo-referenced images are comprised of two files: the image (e.g. image.jpg) and the coordinates file (e.g. image.jpgw). This file has:) |
Anatrancoso (talk | contribs) (creation and import from arcview) |
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| − | + | == What it is== | |
| + | A background image data item consists of an image and its geo-reference, given in the *.img file: | ||
| − | ESRI geo-referenced images are comprised of two files: the image (e.g. image.jpg) and the coordinates | + | IMAGE_FILE : C:\temp\389_.jpg --> Path to the image file |
| + | X : 0 --> Coordinate X of the Upper Left Corner | ||
| + | Y : 0 --> Coordinate Y of the Upper Left Corner | ||
| + | WIDTH : 16008 --> Width in distance units | ||
| + | HEIGHT : 10011 --> Height in distance units | ||
| + | MIP_MAPPED : 1 | ||
| + | MAINTAIN_RATIO : 1 | ||
| + | ALPHA_VALUE : 1 | ||
| + | |||
| + | |||
| + | ==Import ESRI geo-referenced image== | ||
| + | |||
| + | # Add New Item | ||
| + | # Background Image | ||
| + | # In this new layer, go to Properties (F4, or right-click, or Menu Data Items/Properties) | ||
| + | # Choose image file | ||
| + | # Import ArcView GeoRef | ||
| + | |||
| + | ESRI geo-referenced images are comprised of two files: the image (e.g. image.jpg) and the "world file" with the coordinates (e.g. image.jpgw): | ||
| + | |||
| + | 3 --> pixels/unit distance X | ||
| + | 0.000000000000 | ||
| + | 0.000000000000 | ||
| + | -3 --> pixels/unit distance Y | ||
| + | -111989.9 --> Coordinate X of Upper Left Corner | ||
| + | -70266.15 --> Coordinate Y of Upper Left Corner | ||
| + | |||
| + | To convert the world file to Mohid GIS img file, | ||
| + | * WIDTH (HEIGHT) = number of width (height) pixels time pixels/unit distance X (Y). The pixel information of the image can be seen in [http://www.gimp.org/ GIMP], for example. | ||
| + | * The Y coordinate must be decreased by ''height pixels times pixels/unit distance Y'' to go from Upper Left Corner (ESRI) to Lower Left Corner (Mohid GIS) | ||
Revision as of 18:37, 22 December 2008
What it is
A background image data item consists of an image and its geo-reference, given in the *.img file:
IMAGE_FILE : C:\temp\389_.jpg --> Path to the image file X : 0 --> Coordinate X of the Upper Left Corner Y : 0 --> Coordinate Y of the Upper Left Corner WIDTH : 16008 --> Width in distance units HEIGHT : 10011 --> Height in distance units MIP_MAPPED : 1 MAINTAIN_RATIO : 1 ALPHA_VALUE : 1
Import ESRI geo-referenced image
- Add New Item
- Background Image
- In this new layer, go to Properties (F4, or right-click, or Menu Data Items/Properties)
- Choose image file
- Import ArcView GeoRef
ESRI geo-referenced images are comprised of two files: the image (e.g. image.jpg) and the "world file" with the coordinates (e.g. image.jpgw):
3 --> pixels/unit distance X 0.000000000000 0.000000000000 -3 --> pixels/unit distance Y -111989.9 --> Coordinate X of Upper Left Corner -70266.15 --> Coordinate Y of Upper Left Corner
To convert the world file to Mohid GIS img file,
- WIDTH (HEIGHT) = number of width (height) pixels time pixels/unit distance X (Y). The pixel information of the image can be seen in GIMP, for example.
- The Y coordinate must be decreased by height pixels times pixels/unit distance Y to go from Upper Left Corner (ESRI) to Lower Left Corner (Mohid GIS)
