8383 Greenway Blvd., Suite 500
P. O. Box 45137
Madison, WI 53744-5137
AutoCAD R14 Plug-in Version
IcoMap V2.2 $1,995
IcoMap Pro V2.2 $4,995
Stand-alone Version (R14 based)
IcoMap V2.2 $3,495
IcoMap Pro V2.2 $6,495
We live in a digital age, yet we depend on history in many aspects of our daily lives. Change over time, as identified by studying history, is a good indicator of what to expect in the future. Land use changes, property divisions and consolidations, and right of way acquisitions are only a few of the changes important to surveyors. History is preserved, in part, in the form of records created at the time of the event. Modern computer-based analytical tools used for land planning, boundary analysis or project design require that these records be in a computer readable form.
If these records must be converted, the methods will vary with the type of record, the need and the tools at hand. Traditional alternatives include digitizing using a tablet, digitizing using a scanned image as a reference, or automatic raster to vector conversion coupled with manual cleanup. These methods, commonly used for Geographical Information Systems (GIS) needs, are relatively fast, but the resulting vector file is subject to a variety of inaccuracies, consequently limiting the use of the data. If an accurate map is desired, a common method is to key in the bearings, distance and curve information found in the drawing using COGO and CAD drafting tools. This is time consuming.
However, there is an alternative that is both fast and accurate. IcoMap by UCLID Software uses a combination of methods to produce a drawing with a high degree of accuracy, and it is relatively fast.
Converting a Paper Document to a CAD File
The IcoMap process begins with a scanned document that is loaded into a new or existing AutoCAD drawing. Since scanned images can have varying degrees of usability (See "The Good and Bad of Scanned Images"), the first effort would be to apply one or more of the raster editing options to clean up the drawing. IcoMap contains a nice mix of raster editing tools, including erase, draw, crop, scale, rotate, de-speckle and de-skew. Of these, scale is the most commonly used and may be the only one needed if a sharp and clear original is available.
IcoMap uses a technology called "text-to-vector" to convert the raster text into digital vectors(1). Text-to-vector uses a technique called Mathematical Content Recognition (MCR). MCR, a hybrid of optical character recognition (OCR) and intelligent character recognition (ICR), is used to convert raster text to AutoCAD text entities. MCR has the ability to recognize text at any angle as well as to identify signs of mathematical content such as a string of numbers, which may include unit identifiers such as ', ft, mm, etc., or symbols indicating angles.
Once the image is cleaned up and raster text is converted into digital text, the user picks a beginning point and then uses various IcoMap drawing tools to draw lines and arcs. When a direction or distance is required, the user merely clicks on the correct item and the program will use the value, thus eliminating the need to type it in manually. The user then proceeds around the project picking adjacent bearings and distances or relevant curve information if a curve is encountered. As the bearings and distances are selected, IcoMap draws the resultant line or curve on the screen starting at the end of the last line or arc drawn. If the proper values have been selected, the line will lie on top of the raster image, verifying a correct solution as shown in Figure 1. Thus, once started, the user can 'walk" the property by selecting the proper COGO values. Using the same tools, the user can draw connecting interior boundaries.
IcoMap has five different ways to enter curves, depending on the information available:
- tangent-in, radius, delta angle
- tangent-in, radius, chord length
- radius, chord bearing, chord length
- tangent-in, degree of curve, chord length
- radial bearing, radius, arc length
Curve directions are set visually. If the default direction selected by IcoMap is not correct, the user merely clicks the left mouse button to change the direction, then clicks the right mouse button to set it in place. If the user inadvertently sets the curve in the wrong direction, it is necessary to erase and redraw the curve. I would like to see a command to simply reverse the direction of the last curve drawn. I would also like to see the functions of the two buttons reversed since AutoCAD uses the left button to place an object on the screen. I also believe that reversing the functions of these two buttons would be more consistent with the Windows concepts.
Sometimes it is necessary to convert text-to-vector by going in the reverse direction from the way the drawing is annotated. IcoMap provides a handy reverse toggle, which, when a bearing is selected, will draw the line in the opposite direction.
IcoMap has various shortcuts that are quite handy once the user has mastered the basic system. For instance, if a drawing has a series of boundaries sharing a common bearing or with uniform distances, the user can use the right mouse button to repeat the last value. This is especially helpful where there is only one bearing notation for a long series of lots or when the tangent-in bearing is the same as the last line drawn.
Checking for Closures
A GIS system relies heavily on closed polygons. (A polygon may be a parcel boundary, soil boundary, a body of water, etc.) Every polygon must close on itself in order for the GIS system to perform its calculations. The source of the polygon definition will vary but can include parcel maps, plats, easements, deeds and other legal documents of various forms.
As surveyors know, boundaries may not close, even when they appear to do so on a drawing. In order to correct this situation, IcoMap will check closures and flag those areas that don't close within user-specified tolerances. When errors in closure are identified, it's a clue to check for missing legs or errors in entering data. When closure errors are of such magnitude that they don't fall within the user-specified tolerance, manual adjustment must be made. Lest the surveyor get excited, IcoMap draws lines and arcs on two layers. The COGO layer will maintain the integrity of the COGO database, while all adjustments are made on the Parcel Line work layer.
Sounds simple. And it is, once the user gets the hang of the system--and if a sharp (clear) scanned image is possible. But many times it isn't.
When the Scanned Image Isn't Perfect
When MCR can't recognize a text character in a string that otherwise appears to be an annotation, it flags it with a ~. When this text is selected with the cursor, a dialog box appears with possible results as shown in Figure 2. If the correct value is displayed, the user merely selects it and the process continues. If the proper value isn't displayed, the user can edit one of the choices or retype the entire value. This works great if the user can visually identify the correct value. If not, then he or she can switch momentarily to digitize mode and pick a point on the raster image, letting the program compute the correct value.
I found that I needed to verify that all values were converted correctly prior to using text-to-vector. If a value wasn't converted properly, such as a split value, a missing decimal point or numbers converted incorrectly such as shown in Figure 3, yet appeared to be valid annotation data, the program used the value and didn't allow me an opportunity to verify it. However, if I noticed it in time, I could switch momentarily to COGO mode and type in the correct value. While it would slow down the process considerably, I would like an option to let me verify each entry. This would be an asset on images with many conversion problems.
If after using every available raster edit function to get a cleaned up drawing, there are still areas that IcoMap can't recognize, it is simple to switch between the three modes: COGO, digitize and text-to-vector. COGO lets the user enter COGO information from the keyboard, while digitize lets the program compute a distance or direction when the user selects a point on the screen. Of course in the latter option, the accuracy of the existing line is dependent on the ability to select the proper point graphically.
The Real World
I tested the program by using examples from a variety of sources. Charles Phillips, senior vice president at KCI Technologies Inc. in Hunt Valley, Md., provided me with a drawing that was scanned at 400 dpi using a Truescan Select scanner manufactured by VIDAR Systems (Herndon, Va.). The drawing was of a parcel containing 17 straight-line segments and one curve. All of the boundary information data was in a table. Five of the 38 entries contained one character that did not convert correctly. I used the "Edit MCR Text" option to correct these values before continuing with the drawing. Since all the COGO values were in a table, I used IcoMap's split screen option as shown in Figure 4, placing the table in one view, while placing the drawing in another. This allowed me to watch my progress in one view while selecting the COGO values in the other view. It took less than five minutes to correct the values and draw the boundary.
I obtained another drawing from Joel Leininger, principal of S.J. Martenet & Co., Baltimore, Md. S.J. Martenet is an old company with hundreds of drawings dating back to the late 1800s. They recently entered into a partnership with the Maryland State Archives to scan their records into a web-enabled retrieval system, potentially making them available to the entire surveying community.
The drawing used a proprietary font resembling hand lettering. It was scanned at 300 dpi by the State Archives using a Tangent scanner (Tangent Imaging Systems, Littleton, Colo.). This drawing contained easement information in a large number of tables. They were all converted with a high degree of success where numbers were not touching any adjacent mark, such as the minute or second symbol.
I also scanned a small hand-drawn parcel map at 400 dpi on an inexpensive 8.5" x 11" HP Scanjet 3200C (Hewlett Packard, Palo Alto, Calif.), typical of scanners found in many offices. The map had been lettered with a LeRoy font. The number Ã'4Ã was not closed and was consistently converted to the letter "L."
While the electronic age has been with us for a while, the ability to obtain copies of parcel drawings and plats is still largely dependent on the willingness of the originating firm to provide them. The Maryland Archives has recently embarked on a project to scan all the recorded plats in the state and store them on its website. For efficiency, the initial effort scanned existing microfiche cards, which in some cases resulted in raster files that are of a questionable quality. When scanned images aren't useable, they are re-scanned from the original drawing. The ones I downloaded were labeled as being scanned from the original drawing.
The image quality of the Maryland Archive documents was marginal. Decimal points were missing on two of the images. The hand-drawn map had a lot of variation in the spacing and height of text characters resulting in split words and annotations. However, in both cases I could visually identify the text. The third and more recent drawing, although still scanned at 300 dpi, was of much higher quality, and most of the numerical data converted correctly. Thus, even though these images were scanned at a lower resolution than recommended by UCLID, I consider the state archives to be a viable source if scanned documents of a higher quality are not available.
Putting it All Together
One of the benefits of modern technology is to view several parcel maps simultaneously in the proper relationship to each other. The default insertion point for a scanned image is 0,0, which bears no relationship to another parcel. It is necessary to put them together for a composite picture. IcoMap comes with a great system for assembling parcels that are based on the Public Land Survey System found in many parts of the country. This filing system neatly stores all parcels in the correct section, township and range. For these areas, IcoMap provides a mechanism to tie the parcel to the nearest point of commencement, usually a section or quarter corner. Thus all parcels are stored in correct relationship to each other.
In other parts of the country where projects are referenced to a coordinate system, it is necessary to translate the project as a part of the conversion process. This is easily accomplished by moving the entire file, including the raster image so the coordinates match those of the project.
The UCLID program comes with a beginner's manual and a series of tutorials ranging from a high quality scanned image of a simple parcel to a more complex plat with areas that didn't scan well. Running through these tutorials gave me the feel for the program.
The north arrow on some of the drawings I used was not pointing up. Consequently, the first line I drew did not match the line on the raster image. After experimenting with several options, I finally succeeded by using AutoCAD's align command to rotate the entire drawing so the north arrow was pointing up. I later discovered that the rotate command, under raster edit, would accomplish the same thing. The addition of a tutorial where north is not towards the top would be beneficial.
IcoMap comes with an excellent help file that is accessed from the drop down menus. As with most Windows help systems, there is no way to print the entire document except one topic at a time. The addition of a copy of the online reference manual in Acrobat's PDF or other popular format, would be beneficial. In this way, a user could easily print all or portions of the manual for offsite study.
Technical Support and Training
UCLID offers an initial 30 days of free support, after which support is available on a contractual or per-incident basis. E-mail support is less expensive than telephone support. I found E-mail support to be very satisfactory.
UCLID also features a "Knowledge Base" and a "Tech Base" on its website, which are collections of questions and answers. Knowledge Base is available to everyone, while Tech Base is only available to registered users.
Although I found that IcoMap was easy to grasp, a three-day basic training and a two-day advanced training package are available at UCLID's Madison, Wis., headquarters. Training at the user's office is also available.
The majority of the documents I tested were scanned at 300 dpi, less than the 400 recommended by UCLID. In spite of bending the rules considerably, I consider IcoMap a program worth considering, especially if the user has control over the scanning process.
IcoMap seems to do a much better job in recognizing numerical strings than it does on text strings. I don't consider this to be a significant drawback, since IcoMap's function is to find COGO information, which it does very well. When the R2000 version is released later this year, I expect to see many improvements in the ability to recognize both numbers and text.
IcoMap has functions that will appeal to a wide range of users including GIS administrators, surveyors, utility companies and governmental land record departments. In order to meet the needs of both large and small companies, IcoMap comes in two configurations: one that is appended to AutoCAD R14 or Map 2/3, and one that is a stand-alone version built around the AutoCAD R14 engine. Each of these is available in two versions: IcoMap and IcoMap Pro. In addition to the features in IcoMap, the professional version contains batch recognition of images, raster editing, file conversions from various raster formats to TIF, which is preferred by IcoMap, and a Public Land Survey System filing system.
Anyone who has ever made a mistake knows how expensive it can be. A major benefit of using IcoMap is that it combines data entry with error checking. When done properly, the user can visually verify that bearings and distances have been converted correctly prior to picking the value from the screen. In addition, he or she can visually inspect the line or curve just drawn to see that it lies on top of the raster image. Lastly, if desired, the drawing can be plotted with the raster image and the raster annotations compared with those that IcoMap places as the lines are drawn.
IcoMap provides a fast, accurate alternative for entering existing data into a computer. Its prime benefit is speed of data entry for COGO data where high accuracy is required. Small firms, which must enter old data on a regular basis, will find that it doesn't need to be used everyday in order for the operator to remain proficient. Large firms, which manage their own GIS systems or need to integrate drawings in order to analyze large projects, will find it is a valuable tool for entering historical data. GIS administrators will find it a valuable asset when adding a highly accurate layer of survey information from old records. The ability to check for closure errors and make corrections while in the data entry mode will save a lot of time. IcoMap is certainly a product worthy of consideration when a significant number of drawings need to be accurately converted.