The present is the summary of a work Presentadoin the II Conference on Free GIS, by Juan Ramón Mesa Díaz and Jordi Rovira Jofre under the presentation "Comparison of GIS based on free code and commercial GIS" It is a comparison between the GvSIG and Geomedia tools; although it does so without presenting the alternatives that strengthen GvSIG such as SEXTANTE and recent improvements; I think it's a very clever job.
Unfortunately, for this, it is necessary for the post to become long and lose its format for a moment, although it has been somewhat summarized. You can download the full presentation here.
Although I must admit that it is in these posts that I miss Dreamweaver because of the precise control of tables that Wordpress does not allow.
|Basic features.||Project Settings: The two GIS are comparable in possibilities, Geomedia Pro provides the possibility of rotating the map view. Legend management: gvSIG is not up to Geomedia Pro, as it does not incorporate the connection concept, which allows the open layers in the GIS of the existing entities to be independent of the different connections. Editing layers: We highlight the gvSIG drawing command line, CAD style, and the large number of existing hunts in Geomedia Pro. Creation of themes: gvSIG and Geomedia are matched at this point, the two GIS allow the creation with some ease of themes by single value or by rank.||We have given the same weight to the four sections (25% per section). The end result is: Geomedia Pro is slightly above gvSIG in terms of basic functionalities. The section where GvSIG stands out the least is the management of the legend, the cause is its rigidity since it does not allow to hide each weight or insert existing connection entities in the GIS, since the aforementioned orientation towards the connection does not exist.|
|Space Analysis||Features: There are four possible categories of analysis: reclassification by attributes, overlays, buffers, and topological queries. In the four gvSIG and Geomedia Pro, they have functionalities represented. However, in gvSIG the functions have not been fully exploited. Method: From the point of view of a user, Geomedia Pro is easier to use the different functionalities of spatial analysis. In a single screen the user decides which entities he wants to work with, which relationships to apply and which attributes to filter. In gvSIG, all the outputs of the analyzes are saved in a Shapefile file, which implies that to link three different analyzes, it is necessary to create two intermediate files that are not of any use.||Spatial analysis is one of the most important functionalities of a GIS when it comes to generating qualitative information, and above all it is what distinguishes a GIS from a CAD. In this basic aspect we have evaluated two points, the different functionalities (weight 60%) supported by each GIS, and the method (weight 40%) or case of use from the point of view of the user to use spatial analysis. Raster capability: georeferencing, formats, filtering and manipulation. Conclusions: In short, Geomedia Pro stands out in analytical capabilities and in facilities for the user. GvSIG is a very young product, and it still has to improve some of its functionalities.|
|Raster capability||We have evaluated three different concepts in this regard: the georeferencing of images (weight 35%), the visualization of orthophotos (weight 35%); and, filtering and manipulation of georeferenced images (weight 30%). Georeferencing of images: The tool is equally intuitive in the two GIS, but quite unstable in gvSIG, in many cases the operation ends in error, which is why it has been evaluated downwards in gvSIG. Orthophoto Visualization: The wide variety of georeferenced raster formats in which Geomedia Pro and gvSIG can work has been verified. Filtering and Handling: In this section, gvSIG has scored very high thanks to its raster pilot extension. It allows you from analysis of statistical data (histograms) in the images, to the application of filters such as the smoothing by Low step.||Conclusions: The two GIS are matched, the difference is the stability provided by Geomedia Pro to the image georeferencing tool, while gvSIG demonstrates superior filtering and manipulation capabilities thanks to its raster extension.|
|Interoperability||In this aspect the interaction of GIS with other data sources is studied, interoperability is a good differentiator of a GIS. We will globally value the look and divide the data sources into four categories: GIS formats, CAD formats, databases and OGC standards.GIS Formats
|Conclusions: Geomedia Pro is the most interoperable GIS with its great ability to read and write in different data sources (Microsoft Access, Oracle ...), and the ability to export data to CAD formats such as DWG. GvSIG stands out in its willingness to work with OGC standards, and a good predisposition to incorporate Oracle as a database along with PostgreSQL / PostGIS.|
|Performance||To evaluate performance, we wanted to measure overhead (weight 30%), handling speed (weight 30%), and optimization of spatial analysis algorithms (weight 40%). In the Overload measurement, gvSIG was faster than Geomedia Pro. Geomedia results improve measured time by 50%, just by changing the data format from Shapefile to Geomedia Smartstore. In the Speed measurement management we move large volumes of information from one layer to another. GvSIG is again faster than Geomedia Pro. Optimization measure Of spatial analysis algorithms, Geomedia has emerged: tool stability and speed. In gvSIG there are errors caused by your JTS library or your inability to work with certain topologies.||Conclusions: GvSIG is faster than Geomedia Pro, graphing or moving
Data from a layer to a database, large volumes of information. On the other hand, Geomedia Pro stands out in stability and speed when performing spatial analysis, therefore, it is much superior to gvSIG.
|Customizing GIS||We evaluate globally three different questions: that the GIS allows personalization, the type of language or scripts that make it possible; and, the existing documentation. The GIS allow The personalization? In both cases the answer is positive: yes! Types of Language or Scripts, gvSIG has a Scripting language (Jython) and you can also create extensions in Java using the gvSIG classes. In Geomedia Pro it is developed in the Visual Basic languages 6.0 and .Net, with its object libraries to create integrated commands, or programs external to the SIG. Documentation, Geomedia Pro has extensive documentation where each object is described and is rich in examples. In gvSIG, the documentation is sparse and shallow. A description of each component and the gvSIG class architecture is missing, as well as an exhaustive description of the necessary classes.||Conclusions: In the two GIS, the customization solution is well resolved. In the gvSIG documentation the assessment is negative. It is easier for an expert GIS programmer to customize Geomedia Pro than gvSIG, due to the gaps in gvSIG documentation.|
|3D capability||We have evaluated the editing capacity of the Z coordinate (weight 40%), the representation of the territory in 3D (weight 30%); and, the representation of Volumes (weight 30%).||Conclusions: Neither of the two GIS offers serious possibilities in the evaluated sections, only Geomedia Pro stands out in two capacities: Geocoding the Z coordinate and keeping it when exporting to other formats; and, the possibility, with a command created by a company outside of Intergraph, to make extrusions of polygons to volumetries and visualize them from Google Earth or to work with Geomedia Terrain, a complementary product with the desired functionalities. In gvSIG these possibilities will be available in the future released version of gvSIG 3D.|
|Maps||As we have already reflected in the memory of the project, the generation of a Map is the ultimate reason for using a GIS. In this aspect we have evaluated the usability (weight 50%) of the tool and the brightness (weight 50%) of the result. Usability: In Geomedia Pro, the mapping tool could be more intuitive, although the process of creating maps is easy. In gvSIG, we find a tool that is easy to use and at the same time intuitive from the start, less when the scale bar of a map is moved, since the display properties are lost; on the other hand it is compensated with the direct generation of the map to PDF. Vistosity: Both gvSIG and Geomedia Pro provide the user with all the necessary tools to create an attractive map: editing capacity, symbol customization possibilities and scale bars (formats: SVG in gvSIG and WMF in Geomedia), editing of the legend .||Conclusions: The two GIS are equivalent to each other, with two tools for creating and composing very professional maps.|
|Documentation and Support||Insufficient documentation or inadequate support to the user can cause a user to abandon or discard the use of a GIS. To evaluate it, we have divided it into two sections: documentation and support, with an equal weight to assess it globally. Documentation: In the case of Geomedia Pro, the assessment is very positive, there is documentation of all kinds together with the necessary examples, installed together with Geomedia Pro. In gvSIG the fact of having to download all the documentation without a minimum of installed documentation along with the tool and the superficiality of the development documentation forces us not to value this point as much as possible. Support: The experience in this Final Degree Project with gvSIG is that, within three hours, after raising a question with the list of users, an effective response is obtained. Demonstrating the bet made by gvSIG in the user lists. Preventing that at no time a user has the feeling of being alone in front of any incident. Intergraph's many years of experience serving the needs of its users is positively demonstrated. The support provided to Geomedia Pro is carried out in three ways: Knowledge Database, Online and Telephone Support.||Conclusions: In the support provided to the user of the tool, the two GIS are equivalent. In terms of documentation Geomedia Pro passes in front of gvSIG, in quality and exemplification. We highly value the deployment of documentation in the Geomedia Pro when installing the tool, without the user having to go to web links to get all the necessary documentation as in gvSIG.|
|Economic aspects||The costs of each GIS (license, training, customization, maintenance…) have been reasoned, exemplifying the economic cost of 'implementing a license during the first two years; and, assessing whether the price matches the product.||Conclusions: The cost of Geomedia Pro is higher than that of gvSIG, however, Geomedia Pro is a very stable product with a good support response from Intergraph. The answer would be: the two GIS have the price they cost.|
|License Fee 13.000-14.000 €||0 €|
|License maintenance cost 2.250 €||0 €|
|Support Cost Included in the maintenance cost: telephone support, user list; and, if the volume of licenses is important, in-person technical to the client's offices.||0 €, the support system is based on user lists and the resolution of a doubt is done in 24-48h.|
|Cost of training 900 € 27 hours in 5 days||300 € a course of 20 hours.|
|Customization cost 500 € -700 € man / day||240 € - 320 € man / day.|
In the results table, we show the evaluation of each aspect; And, the overall assessment of each GIS; Weighted from 1 to 5 where originally although I translated it from 0% to 100%: 20% is def
40% is insufficient, 60% is sufficient, 80% is remarkable; And, 100% is excellent. It is interesting that in general, gvSIG has a very interesting tendency to become a fairly stable alternative, especially because it has a well-defined medium-term development plan.
|Aspect Ratio||Geomedia Pro||GvSIG|
|Basic Features of a GIS||100%||80%|
|Interoperability with different data sources||100%||80%|
|Personalization Capability, Scripts or non-GIS languages||100%||60%|
|Economic aspects to be assessed||100%||100%|
|GIS global rating||100%||80%|