IMPIMA - Image Conversion
To handle images in other formats such as TIFF, RAW and SITIM (INPE format),
in SPRING projects, these images have to be first converted to a format accepted by the Spring system,
so they can be registered. The procedure is close to reading, first the image parameters are loaded,
then a Quick Look is performed if desired, the bands are selected and the output image is recorded. The
basic difference is that the source image can be in any directory in the file system.
NOTE: In case of SITIM images without the file descriptor (*.d), the images can be converted
to GRIB using the RAW format, if the number of rows and columns is known for the image.
Loading IMPIMA
Once SPRING is correctly installed, the user can access the Impima module.
How to load IMPIMA :
- load the x-win environment (motif, openw, startx ;etc.);
- from a command window (comandtool, aixterm, etc.) type
"impima".
Next, the procedures to convert an image are presented, this procedure has to be followed in the same sequence:
- Load the image parameters:
- How to make a Quick Look:
- Select the region of interest
- Select the bands to be loaded
- Create an output image (grib file)
How to load the image parameters:
- click on Format to select among TIFF, RAW or SITIM;
- click on Directory...
to inform the path where the image to be converted is stored, or just type the path in the text box and
click on CR. If the image is in a CD-ROM, the CD-ROM has
to be mounted in the file system (e.g.: /cdrom). Notice that the existing files are presented in the Files
list;
- click on the image file in the Files list. Notice that the bands, in case there are more than one,
appears in the side list. The image parameters presented are: Sensor (Optical or Radar...),
Resolution and Coordinates. In case the image corresponding sensor is a Radar, it will be required to inform the
radar parameters. These parameters are stored together with the output image file.
NOTE: After reading the image parameters it is possible to load the image directly to the disk unit,
that is, to create an output image (*.grb), or select a smaller region giving the desired coordinates directly,
or even, using the area selection by the cursor, which requires a Quick Look.
NOTE: The process to perform a Quick Look is the same described for image reading. See in the
topic below Selection by the Cursor . Only when the image is presented in the window, the
Selection by the Cursor button becomes active.
Selection by the Cursor
How to make a Quick Look:
- to make a quick look select a band in the listing box Bands;
- click on the Quick-look button
to load the selected band. Notice that the sampling factor and the resolution are automatically
changed so the whole scene can be presented in the drawing area.
NOTE: The Sampling Factor for the quick look is defined such that the image is
presented with the best resolution possible in the window with fixed size (1000 x 1000 pixels) in the
RISC workstations version. For instance, for an image with 30m spatial resolution when reading a
quadrant with 3000 x 3000 pixels, the algorithm divides the image size by window size, resulting in a
sampling factor equals to 3, that is, a spatial resolution of 90m. If the sampling factor is different
than 1, when executing a reading, the output image spatial resolution will be divided by the
sampling factor.
Only after the image is presented in the window, the selection by the cursor button becomes
active.
How to select part of an image using the cursor:
- define the area of interest in the drawing area using the cursor to indicate the extreme points upper
left corner and lower right corner (in this order) using the mouse LB;
- to remove the marked area use the mouse RB;
- once the area is defined click on the Selection by the cursor
button. Notice that the coordinates are updated according to the area selected by the cursor.
Defining the Output Image
Once the bands to be loaded and the coordinates are defined (via selection by the cursor or typing the values
directly), the next step is to definitely load the Output Image.
NOTE: In case the Coordinate values are not changed after loading the parameters, all the
image will be loaded.
How to create an output image:
- click on the bands which will be read;
- click on the Directory... button
to inform where the output image will be stored, or type the path directly in the text box;
- click on the Name text box and type the name of the output image, without any extension,
because IMPIMA puts the "grb" extension automatically;
- define the Sampling Factor. A value equals to 1 means to keep the spatial resolution of the
original image. Do not forget to click on CR;
- click on the Apply button to read the image.
After reading the image the Drawing and
Reset buttons become active allowing the image visualization, using
the desired bands.
NOTE: Once the image is read, this is stored automatically in the disk using the *.grb
extension. Thus, this image file is ready to be georeferenced in the SPRING module, and can be included in a project,
for further treatment.
Reading Images using Impima.
See also:
About Image Registration
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