Input File
Select the imagery raster that you want to warp, from the drop-down list or browse to a file location to select an imagery raster as input file.
Warp Options
To warp a raster dataset, you can choose one of the following transform types.
- Automatic - A simple, linear transformation defined by a scaling factor and two pairs of common coordinates or one pair of coordinates and a bearing difference. This transformation provides only rotation and shift.
- Conformal - Conformal transformations preserve shapes and angles and may include a rotation, a scaling and a translation. Straight lines and parallel lines remain straight and parallel in the output image. A minimum of three control points are required for a conformal transformation.
- Affine - A linear transformation with separate scaling, rotation and shift along the X and Y axes. This is an extremely useful transformation and can be used where you need to adjust from an unknown coordinate system such as a local Mine Grid to UTM. The Mine Grids can be translated to UTM by rotating around the X,Y and Z axes. For example, transform a non-earth local grid to MGA94 (GDA94) Zone 54. An affine transformation establishes a correspondence between three points in the source image and three points in the destination image.
- Projective - Projective transformations maps lines to lines. Straight lines remain straight but parallelism may not be preserved. Four control points are required for a projective transformation.
- 2nd Order Polynomial - Polynomial transformations are higher-order, non-linear transformations which can handle more complex local distortions. Polynomial transformations are commonly used for image registration and correction of distortions in remote sensing applications. Polynomial transformations are smooth and are also known as ‘rubber-sheet’ transformations as they enable parts of an image to be stretched or warped to fit the control points. You need a minimum of nine control points for 2nd order polynomial.
- 3rd Order Polynomial - It requires a minimum of sixteen control points.
More Options
Click More Options to specify the cell size for the output raster. The cell size defines the width and height of a raster cell in distance units. If the raster cells are square both width and height are specified with same value.
By default, Automatic is selected which means MapInfo Pro Advanced will calculate the output raster cell size based on source data points. The warp operation chooses an output raster cell size that is similar to the size of the source raster pixel.
If you wish, you can manually enter the cell origin by clicking the Define Cell Origin check box.
Control Points
Control Points are a list of image coordinates and their corresponding world coordinates. If the input raster that you choose for warping already has a .TAB file associated with it then you are prompted whether you want to load the control points from the TAB file. Click Yes if you want to load them. The control points from the .TAB file will be displayed in the control points grid. If you select No, you need to load them manually via the Load button or enter them individually.
Test Control Points - When you click Test Control Points, the RMS, Error X and Error Y values are computed from the input control points. Click this to use control points from the input raster's associated .TAB file.
The Load button enables you to load the control points from a .TAB file or a .csv file.
The Save As button enables you to save control points to a .csv file.
Control Points grid:
- Use - The Use column in the control points grid allows you to enable/disable a particular control point that will be used for the warp function without deleting them from the grid.
- Label - The label for this control point.
- Image X - Image column.
- Image Y - Image row.
- World X - World X coordinate.
- World Y - World Y coordinate.
- RMS - This is the root mean square error for each image control point. It is calculated as the distance between each input Image X (control point) and output Image X control point.
- Error X - This is the estimated error (distance) in pixels between the image X input control point and corresponding output image X control point as determined by the chosen transform.
- Error Y - This is the estimated error (distance) in pixels between the image Y input control point and corresponding output image Y control point as determined by the chosen transform.
- Selected Transform Type - It displays the transform type (along with standard deviation) when you click the Test Control Points button.
Standard Error X, Y -
Pixel Y coordinates are often measured from the top left corner downwards. For example, if you view an image in Microsoft Paint then it will give the top left pixel coordinate as (0,0). Select this option to indicate this is the sense of your Y pixel coordinates.
Projection
Specify the projection for the output file. If you are loading control points from the input TAB file, the projection values are read from the input file. If the input TAB file does not contain control points you need to enter them manually.
- Category - The Category drop-down list consists of all projection systems supported by MapInfo Pro. For example, Longitude/Latitude, Universal Transverse Mercator (ED 50), Universal Transverse Mercator (NAD 27 for Canada), etc.
- Sub-Category - The Sub-Category drop-down list consists of the type of projection based on the selected projection system.
MVR Options
Output File
Specify a name, location and format for the output raster that you are creating. In the
Output File box enter the name you want to specify for
your output file. Click 
to browse to the location in
your computer to save the output file. You can also select the required output file
format.
Click Output Settings to specify the following. The values in Output Settings are controlled by the Raster Preferences dialog; however, you can override those settings here.
Display Output File - Select the check-box, if you want to open the output file in the Map window on completion of the operation. You can configure to make this the default behavior from the Raster Preferences dialog.
If the output file format is an MRR or a TIFF, additional options appear. The available options are listed below.
- Compression Settings
- Data Balanced
- Data Speed
- Data Space
- Advanced
The Data Balanced option allows you to achieve a balance between speed of operation and file size. The system selects the best combination of speed and space for you. With the other two options Data Speed and Data Space, you can choose between speed of operation and storage space. Choose Advanced option to set the advanced compression settings such as compression method, level, and encoding type. For details on the Advanced option, see Compression Settings.
- Compression- Select a suitable compression method and level for the data. For more information on compression, see Compression methods.
- Encoding Type - Select a suitable Encoding Type for the data from the list. It enables you to compress the data when saving a raster to MRR format. Encoding Type is enabled only when the raster field type is Continuous and the compression method is lossless such as ZIP, LZMA or LZ4. The drop-down list contains the following:
- None - No encoding.
- Previous Column Linear - Performs linear estimation of the value from previous two columns.
- Previous Column Value - Predicts the value from previous column.