mouza map digitizing using arcscan

M O U Z A M A P D I G I T I Z I N G

Sourav Bhadrasbhadra019@gmail.com

M O U Z A M A P D I G I T I Z I N G

“Mouza” is a geographic extent using widely in Bangladesh since early 19th century. Generally mouza is required very much at the time of land purchasing or selling. Urban planners and other decision makers often need super imposed mouza maps in digital format for implementing development projects. So the

old, hand drawn mouza maps are needed to be digitized in vector format then.

ArcScan extension of ArcGIS is a fantastic option to vectorize the Mouza Maps automatically. But the process is not an one tool approach. The whole process is displayed in this slide as much as I could. But I

request you to not follow the process blindly. Understand the basics.

Any suggestions will be welcomed. Enjoy.

10/02/2016

M O U Z A M A P D I G I T I Z I N GMouza Map Collection and Scanning in Full Size

• At first the mouzamaps are neededto be collectedand scanned indigital format atbest resolutionpossible (bydefault it would be.jpg)

M O U Z A M A P D I G I T I Z I N GConversion of Raster in Grey Scale

• The scannedimages are savedin .jpg extension

• It is needed to beconverted into .tifextension, which isa grey scale format

• A TIFF format cansupport classifiedcolor ranges whichis very muchrequired forvectorization

• .img format is alsopreferable by theway

• Its users choice.

M O U Z A M A P D I G I T I Z I N GConversion of Raster in Grey Scale

• Right click on thelayer and click on“Export Data”

M O U Z A M A P D I G I T I Z I N GConversion of Raster in Grey Scale

• Export the .jpginto TIFF extensionin desired location

• Try to do thisactions in a sameworkplace/folder

M O U Z A M A P D I G I T I Z I N GConversion of Raster in Grey Scale

• Find it as .tifextension

• You can see thatthe color rangesare showing as“Stretched” colorramp

• But we need twocolors showingBlack or otherdarker colors asForeground Colorand white or NoColor asBackground Color

• That why theimage is neededto be classifiedinto two classes.

M O U Z A M A P D I G I T I Z I N GReclassify the Color Class

• Go to the “LayerProperties”

• Click “Symbology”• Pick “Classified”

range• Select “Classes” as

2, which will selectonly 2 classes ofcolor to berepresented

• Put the range to177 (or closer tothis value) forDarker/Foregroundcolor

• Select “No Color”for the other class

M O U Z A M A P D I G I T I Z I N GReclassify the Color Class

• This will be theoutput

• There is now onlytwo classes for theimage layer

M O U Z A M A P D I G I T I Z I N GClean the Raster Image

• To start editing ofthe workflow a“Dummy Layer”should be includedin the sameworkplace wherethe .tif is stored

• The Dummy Layeris actually adummy one. Thislayer just start theediting process. Ifyou have othervector files inworkspace, don’tneed to create adummy layer orvector

M O U Z A M A P D I G I T I Z I N GClean the Raster Image

• Start editing theDummy Layer

• Open “ArcScan”• You are using

crack of ArcGIS forsure. So check thatthe ArcScan ischecked on in theCustomize >Extensionswindow.Otherwise it won’twork

• Click “RasterCleanup”

• Click “StartCleanup”

• You can clean theraster image usingthis tool (i.e.unnecessarywriteups)

M O U Z A M A P D I G I T I Z I N GClean the Raster Image

• Click “CellSelection”

• Click “SelectConnected Cells…”

M O U Z A M A P D I G I T I Z I N GClean the Raster Image

• Choose“Foreground” asto search forconnected cells

• Enter a value inthe “Enter totalarea”

• This valuedetermines howmany connectedcells will beselected. Thedefault value is300. It can beincreased

M O U Z A M A P D I G I T I Z I N GClean the Raster Image

• Clcik “RasterCleanup”

• Click “EraseSelected Cells”

• This would erasethe connectedcells of similarvalue

M O U Z A M A P D I G I T I Z I N GClean the Raster Image

• But the process isa little bit lengthy.

• You have to iteratethe processmultiple timesuntil the desiredoutput comes

• Yes, doing this inArcMap is little bitslow and irritating.

• You can do thisusing Photoshopor ACD See orCorel Paint orother photoediting softwares.

• But if you don’twant to insultArcMap…. Be myguest.

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• Select the layer tobe scanned in the“ArcScan” toolbar

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• Click“Vectorization”and then“VectorizationSettings” tochange theparameters

• The vectorizationoutput dependson theseparameters

• The parameterscould not be fixedfor every imagebecause itdepends on thequality of yourimage

• But you can keepthe defaultparameters

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• Click“Vectorization”and then“VectorizationOptions” to checkall the outputs tobe required

• The method hereshould be“Centerline”

• The “Outline”check would resultin creating lines bythe both sides ofraster line, but youdon’t want that

• Check the“Foreground” and“Background”color if these areok

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• Create a Polylineshapefile wherethe vectorizedoutput will besaved

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• Click “StartEditing” of theLine

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• Click“Vectorization”

• Then click“GenerateFeatures”

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• Select theTemplate as Line

• You can check on apolygon if youwant the outputas in editablePolygon shapefile

• But it is better todo this in polyline

• Because inpolygon only theclosing lines willcreate a polygon

• But the non-closing lines wouldnot result in

• If you do this inpolyline and thenconvert it intopolygon, you cancheck either allthe outputs are ok

• But your wish

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• The process willbe shown in aprogress bar

• It will take sometime though

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• This is the finaloutput in linefeature

M O U Z A M A P D I G I T I Z I N GVectorizing Process

• But everything isconverted intovector lines.

• That is a totalmess!!!!

M O U Z A M A P D I G I T I Z I N GConverting Vector Lines into Polygons

• Then the line isneeded to beconverted intopolygon

• Arc Toolbox > DataManagementTools > Features >Feature to Polygon

M O U Z A M A P D I G I T I Z I N GConverting Vector Lines into Polygons

• This is the output• But this is another

mess• Because the

closing lines ofletters andnumbers is alsoshowing smallerpolygons

• You have to mergethe extra polygonsmanually with themain polygon

M O U Z A M A P D I G I T I Z I N GPlot ID Detection

• Then the plot IDsshould be insertedmanually

• You have torecheck everyplots becausesome lines maynot be vectorized

M O U Z A M A P D I G I T I Z I N G

• The process is not easy or one click or one tool approach• Many specialists are still working on automating the whole process

• But until then it could be a better option• If anything is easier or if there is any mistake in this process, please feel free to comment

• I’ll be really obliged

Thank You

10/02/2016