Reading Images using Spring (old module Impima)

Loading Spring

The Windows version do not allow access to images from magnetic tapes. Other files recorded in CDs or other media are accessible.

Check below the steps you need to follow.

Running "Spring":

  • after downloading and installing SPRING, you can access "Spring" module through the file "spring.exe" or using shortcut created on your desktop;
  • click on Start - Programs - Spring and choose Spring.

 

Operating the SPRINGmodule

Loading an Image:

  • open the Spring module as described above;
  • click on File - Open Image on the main menu . The window "Image Viewer" (Open) is shown (check more details on how to operate it);
  • select in "Examinar" (Choose) the drive where the image you want to read is located;
  • select in "Arquivos do Tipo:" (Directory) the image format:
    • TIFF e GEOTIFF (*.tif) files;
    • Volume Directory (vold*.dat) for Landsat or SPOT images, BSQ and BIL formats respectively;
    • Fast Format files (HEADER.dat);
    • GRIB files (*.grb) for images already read by "Impima" and saved in this format;
    • SPG files (*.spg)
    • SITIM (*.d) files (Sitim-INPE format);
    • RAW files (*.*) for raw images;
  • select the image file that corresponds to the format chosen and click on "Abrir" (Open);
  • observe that the Input Image Parameters come along and are presented;
  • choose on the Bands list one of the images (if there is more than one);
  • click on Apply - Draw on the main menu or . In case the image is in TIFF format, you will need to inform the Pixel Size in meters. For images in RAW format, you will need to inform the number of Col x Lin (Columns x Lines) and Pixel Size in meters. The image is presented on the drawing area.

NOTES:

  1. Only one band (monochromatic image) can be visualized on "Spring", even if there are more than one band on the image file.
  2. For TM/Landsat-5 GEOTIFF images, it is possible to supply, as an input parameter, the WRS (World Reference System), since this information is not defined for this format.

The system always shows the whole image on "Spring" display. Therefore, most of the times, the image is resampled. For practical reasons, the system automatically calculates the resampling factor when the image is greater than 1500 lines x 1500 columns.

If you want to select (cut) a smaller region of the image, you should first present the whole image on the screen.


To select and record a smaller area:

  • Load the image as described above. Observe that the cursor is permanently shown in the Zoom Cursor mode (see more details about Zoom Cursor);
  • Click on the first point (top left) over the image and diagonally drag to the second point (bottom right), defining a rectangle over the image;
  • Choose Apply - Draw or . The image is zoomed inside the delimited region. Observe that the line and column values are presented on the Output Image Parameters.

NOTE: If you wish, you can type in directly the values of X1,Y1 and X2,Y2 on the correspondent fields. Then, choose Apply - Draw or .

To see the whole image again, use the button Reset or Apply - Reset on the main menu. In this case, the minimum and maximum values are presented.



For easier location of the interest area, use the linear contrast over the image:

To enhance an image:

  • Load the image (or a region of interest) as described above;
  • Click on the button Enhance . The "Enhancement" window is presented;
  • Click on the button and drag it horizontally. When you release the mouse, the contrast will be applied to the image. Adjust the contrast as you wish.

After choosing the region on the image to be recorded, save it on SPG format so it can be used on the "Spring" module.

Pay attention when you define the output image pixel size and sampling factor. Incorrect values can produce incoherent output when registering the image. TIFF e RAW images do not contain the information about spatial resolution of the sensor used, so try to find out or calculate the image pixel size in meters beforehand. You will need this information.

Saving images on SPG format:

  • Select the Band(s) for the output image;
  • Select the Sampling factor. If you wish to keep the original pixel size, use Sampling 1;
  • Click on File - Salve As... or . The window "Salvar Como" (Save as) is presented ( see details on how to operate it);
  • Type the SPG filename and click in "Salvar" (Save).


NOTE: When the image is from the TM-Landsat sensor, level 5 or 6, the version of "Spring" (3.1.1 or later) will keep the geometric correction that already comes with this kind of image, even if you resize or cut the image. The image registration for this kind of image, can be performed with only one control point.


See also:
Digital Images
Remote Sensing
Image Registration