ER Mapper ER Mapper is one of the software (software) used to process data or satellite imagery. There are many other software that can also be used to process image data, such as Idrisi, Erdas Imagine, PCI and others. Each software has its own benefits and advantages. ER Mapper can be run on a workstation with the UNIX operating system and computer PCs (Personal Computers) with operating system Windows 95 upwards and Windows NT. Image data processing is a way of manipulating the image data or processing an image into an output data (output) in accordance with what we expect. The way of processing the image data itself through several stages, until it becomes an output that is expected. The purpose of image processing is to sharpen the geographical data in digital form into a view that is more meaningful to users, can provide quantitative information of an object, and can solve the problem. Betuk digital data stored in two-dimensional rows of small squares called pixels (picture elements). Each pixel represents an area that is on the surface of the earth. This structure is sometimes also called the raster, so that image data is often also called raster data. Raster data consists of rows and columns and each pixel on the raster data has a digital value (Figure 1).

Data obtained from satellites are generally comprised several bands (layers) that covers the same territory. Each of the bands recorded the reflection of objects from the earth's surface at different wavelengths. This data is also called multispectral data. In image processing, also made the merger a combination of several bands for extracting information from specific objects such as vegetation index, parameters of water quality, coral reefs and others. A. Image Data Processing Applications Image data processing is an important part in order to analyze geo information through satellite remote sensing data. Applications that can be applied through image data processing, among others: o environmental monitoring o management and urban planning and urban areas o management of forest resources o mineral exploration o agriculture and plantation o management of water resources o management of coastal and ocean resources o physical oceanography o exploration and production of oil and gas B. Image Data Processing Image data processing began in the 1960s to process imagery from satellites around the earth. Processing of image data created in the form of "disk to disk" where we have to write the specification file to be processed, then choose the type of processing that will be used, then wait for the computer to process the data and write the result into a new file (Figure 2). So until the final file the new form we can see the expected results, but if the results are far from what we expect, then we must repeat from the beginning again. Until the 1980s the process is still used by some image data processing products.


ER Mapper develops new image processing method with an interactive approach, where we can immediately see the results of any treatment of the images on a computer monitor. ER Mapper provides convenience in data processing so that we can combine various image processing operations and results can be directly seen without waiting for the computer to write a new file (figure 3). How this processing in ER Mapper is called Algorithm.


The algorithm is a series of step by step processing in ER Mapper or command that is used to transform the original data from your hard disk or instructions until the process is complete. With the algorithm, we can see the results that we did on the monitor, store them in storage media (hard disks, etc.), redial, or change it, every time. Therefore algorithm only contains a series of processes, then the file size of the algorithm is very small, only a few kilobytes to several megabytes, depending on size of the process that we do, so it saves space on your hard disk. And because the files are small algorithm, the image delivery process becomes relatively more quickly. This makes the processing faster. The concept of this algorithm is one of the benefits of ER Mapper. In addition, several other peculiarities are owned by ER Mapper: 1. Powered by 130 importing data format 2. Backed with 250 format printing output data 3. Three-dimensional visualization 4. Dynamic facility Links 5. Liaison dynamic (Dynamic Links) ER Mapper is a special facility that allows users to instantly display an   
    external file data in the image without the need to import them first. Data that can be connected including in
    the popular file formats such as ARC / INFO, Oracle, and standard file formats like DXF, etc. DON.     In addition to the above advantages, ER Mapper has limitations, namely: 6. The limited format of exporting data 7. Data is data that can handle 8 bits.

7. Printing     Users can generate an output image using the printing equipment or a printer that includes a color printer, film, black and white printers and graphic formats. Printing options require an algorithm that defines all the data and its processing by the algorithm only records that have been stored that can be printed. Make sure we have saved our algorithm before printing.
6. Map Composition     The composition of the map allows users to present images in a professional and meaningful. Kartografik quality maps in ER Mapper to create a grid, legend, scale bar, north arrow, company logo, legend classification.
5. Dynamic Links     Liaison dynamic ER Mapper is a special facility that allows users to instantly display an external file data in the image without the need to import them first. Data that can be connected including in the popular file formats such as ARC / INFO, Oracle, and standard file formats like DXF, DGN etc..
4. Image sharpening      Image sharpening process carried out to facilitate the user in interpreting the existing objects in the image display. With the algorithm, ER Mapper allows the user to do various kinds of image sharpening process without the need to create new files that will only make a full disk computer. The types of image enhancement operations include:  Merging Data (Data fusion), combines images from different sources in the same area to assist in the interpretation. Examples of Landsat-TM data with SPOT data.  Colodraping, put one type of image data on which other data to create a combination of the display making it easier to analyze two or more variables. Examples of vegetation from satellite imagery on the above image colordraping aerial photographs in the same area.  Sharpening contrast, improving image appearance by maximizing the contrast between lighting and darkening or raise and lower the price of an image data.  Filtering, improve the appearance of the image by transforming the digital image values, such as border area mempeunyai sharpen the same digital value (enhance edges), smooth the image of the noise (smooth noise), etc..  Formula, makes a mathematical operation and incorporate the values ​​of digital images on these mathematical operations., Such as Principal Component Analysis (PCA).  Classification, featuring the image of a certain class of statistics based on the value of digital. Examples of land cover maps from Landsat-TM satellite imagery.
3. Image Mosaics     Mosaic image is the process of combining / paste two or more images that overlap (overlapping) so that the image of a representative and continuous. In ER Mapper This process can be done without creating a large file, except when we want to save into a separate file.
2. Rectification Data / Geocoding     Raster data is generally displayed in the form of "raw" data and has a geometric error. To obtain accurate data, the data must be geometrically corrected into the earth coordinate system. There are two geometric correction process:  Registration, geometric correction between the images that have not been corrected with the image that has been corrected.  rectification, geometric correction between the images with map
1. Displaying Images     After the process of importing data, next is to display the image. This is done to determine the quality of data used. If the data / image quality is not in accordance with the wishes (cloudy, data is striped, etc.) then we do not need to continue the treatment process, and look for new data which has better quality. In ER Mapper, I view the images called Color Mode. There are several ways to display the image:  Pseudocolor Displays, displays the image in black and white, usually only consists of one layer / band only.  Red-Green-Blue (RGB), displaying the image through a combination of three bands, each band was placed on a single layer (Red / Green / Blue), this method is also called color composite. Example: False Color Composite RGB 453.  Hue-Saturation-Intensity (HIS), displaying the image through a combination of three bands, each band was placed on a single layer (Hue / Saturation / Intensity), this method is usually used when we use two different kinds of data, eg radar data with Landsat data -TM.
C. Image Data Processing Procedures Image data processing procedure begins by importing the data up to the final result in print (printing). From some of these procedures, not all procedures must be executed to obtain results in line with expectations. For some applications the expected output can be produced without going through the entire image processing procedure. 0. Import Data The first step in image processing is the import of satellite data to be used into the ER Mapper format. Typically data is stored in the form of magnetic tape, CD-ROM or other storage media. Two major forms of data are imported into ER Mapper is raster and vector data. Raster data is the data type that became the main ingredient of image processing. Examples of raster data is satellite imagery and aerial photography. At the time of import raster data, ER Mapper will create two files, namely:  binary data file that contains the raster data in BIL format, without the file extension.  The header file in ASCII format with extension. Ers Vector data is data that terseimpan in the form of lines, points and polygons. Examples of vector data is data generated from the digitized Geographic Information System (GIS) such as roads, sampling sites or administrative boundaries. ER Mapper also will create two files are the result of importing the data vector:  Data files in ASCII format containing vector data  The header file in ASCII format with extension. Erv