Mosiacing the images

Mosiacing is the process of joining geo-referenced images together to form a larger image or a set of images. The input images must all contain map and projection information; all input images must have the same number of layers.
1. Before Mosiacing the Images, observe the images, which are rectified just now.
2. Click on the DATAPREP Icon of the MAIN TOOL Window
3. Click on MAOSAIC IMAGES option. Then it will display the MOSAIC TOOL Window as shown below

1. Input the Images for Mosiacing

4. Click on EDIT Menu on the MOSAIC Window
5. Click on IMAGE LIST option. Then it will display IMAGES LIST Window as shown Below

6. Click on, ADD to get ADD IMAGES FOR MOSAIC Window
7. Select the Image LS_IMAGE_F11.IMG file from Folder D:\ERDAS_Exercise_Files
8. Keep the default option for METHOD as INDIVIDUAL FILE
9. Keep the Default option USE ENTIRE IMAGE as the option for IMAGE AREA OPTION
10. Click on ADD to add the file in IMAGE LIST window.
11. Similarly ADD the image LS_IMAGE_F12.IMG to the IMAGE LIST window
12. Click on, CLOSE option to Exit from ADD IMAGES FOR MOSAIC Window
13. Click on, CLOSE option to Exit from IMAGES LIST Window
14. Observe that the two images outlines are displayed in the MOSAIC TOOL Window

ii. Image Matching

15. Click on EDIT menu of the MOSAIC TOOLS Window
16. Click on IMAGE MATCHING option. Then it will display the MACTHING OPTION window as shown below

17. Keep all the Default option i.e
Matching Method: OVERALAP AREAS
Histogram Type: BAND-BY-BAND
18. Click OK

iii. Set Overlap Functions

19. Click on EDIT menu of the MOSAIC TOOLS Window
20. Click on SET OVERLAP FUCTION option. Then it will display the SET OVERLAP FUCTION window as shown below

21. Keep the Default Option such as

Intersection Type: NO CUTLINE EXISTS
Select Function: OVERLAY

22. Click on APPLY
23. Click on CLOSE to Exit from SET OVERLAY FUCTION window
iv. Mosaic Output
24. Click on EDIT menu of the MOSAIC TOOLS Window
25. Click on OUTPUT OPTION. Then it will display the OUTPUT IMAGE OPTIONS window as shown below

Keep the Default option UNION OF ALL INPUTS for OUTPUT IMAGE OPTION
27. Click on PROCESS Menu of the MOSAIC TOOL Window
28. Click on RUN MOSAIC Option to get the Run Mosaic Window as shown Below

29. Browse for the Folder D:\ERDAS_Exercise and Type the Output File Name as MOSAIC_IMAGES.IMG
30. Check the Option for OUTPUT A COMMON LOOKUP TABLE
31. Also Check the option for STAT IGNORES VALUE AS 0
32. Click on OK To start the Process of Mosiacing the Images
33. If you want to save this mosaic tools save it, other wise close the mosaic tools window

v. Viewing the MOSAIC Image

1. Click on VIEWER Icon of the Main Tool Bar
2. Select Viewer type as CLASSIC VIEWER
3. Click OK to get a blank Viewer Window
4. Click on OPEN
5. Select RASTER LAYER option
6. Then Browse for the File MOSAIC_IMAGES.IMG and select the same file
7. Right Click the mouse button and select IMAGE FIT TO WINDOW Option

Then observe the overlap area of the images, you don’t find any differences.