Performance of Map Symbol and Label Design with Format and Display Resolution Options Through Scale for The National Map

Transcription

1 Performance of Map Symbol and Label Design with Format and Display Resolution Options Through Scale for The National Map Follow-up on AutoCarto 2011 talk Cynthia A. Brewer, Pennsylvania State University Penn State Research Assistants: Paulo Raposo, Chelsea Hanchett, Andrew Stauffer

2 Multiscale topographic map design Draft design for mapping from The National Map data Suited to multiple resolutions Onscreen 91 ppi (desktop) 120 ppi (laptop) Print 400 ppi Suited to multiple formats PDF ArcMap Cached tile (web) Print Supports hydrographic generalization evaluation

3 Quality rating categories A - Label appearance and readability B - Label positioning and generalization C - Point symbol appearance D - Point generalization E - Line symbol appearance F - Line generalization G - Area symbol appearance H - Area generalization I - Terrain appearance J - Terrain generalization K - Vertical integration between layers L - Overall appearance of map (Goldilocks)

4 Quality rating categories E - Line symbol appearance Line appearance too similar to other line symbols Line too wide (or too narrow) Line form is jagged (due to rendering) Poor pattern choice (e.g., dash) Poor multilayer pattern combination (e.g., dash, centerline, line casing) Poor color(s) Interference from other features above or below line Poor symbol-level drawing (line should be above or below another feature type)

5 WV 1:24K C. Brewer, NationalMapping.us CEGIS, June 2011

6 WV 1:50K C. Brewer, NationalMapping.us CEGIS, June 2011

7 WV 1:100K C. Brewer, NationalMapping.us CEGIS, June 2011

8 WV 1:250K C. Brewer, NationalMapping.us CEGIS, June 2011

9 WV 1:500K C. Brewer, NationalMapping.us CEGIS, June 2011

10 WV 1:1M C. Brewer, NationalMapping.us CEGIS, June 2011

11 Example ratings aggregation

12 Experiment design 5-inch map patches examined: by 3 raters at 6 scales for 8 subbasins at 2 resolutions in 2 file formats 3 x 6 x 8 x 2 x 2 = 576 evaluated (June 2011)

13 Quality ratings results Comments on problems: # % A - Label appearance and readability B - Label positioning and generalization C - Point symbol appearance D - Point generalization 74 3 E - Line symbol appearance F - Line generalization G - Area symbol appearance H - Area generalization I - Terrain appearance J - Terrain generalization K - Vertical integration between layers L - Overall appearance of map Total comments: 2627 Labels 28% Lines 26% Labels and lines together 54% of issues

14 E - Line symbol appearance Quality ratings results A - Label appearance and readability B - Label positioning and generalization C - Point symbol appearance 10 F - Line generalization 10 G - Area symbol appearance 7 L - Overall appearance of map 7 K - Vertical integration between layers 6 H - Area generalization 5 I - Terrain appearance 5 J - Terrain generalization 4 D - Point generalization 2 % 17 = 10 Arc + 6 PDF 15 = 10 Arc + 6 PDF 13 = 7 Arc + 6 PDF Overall, 1.4x as many problems in ArcMap views than PDF

15 Quality ratings results Largest differences between Arc and PDF ratings in appearance categories: Category Arc Comments PDF Comments Label appearance Line appearance Point appearance Terrain appearance Less difference on more data-driven issues: Category Arc Comments PDF Comments Vertical integration Terrain generalization 61 50

16 Quality ratings results Most issues at middle scales: Scale % share of all comments 24K 14 50K K K K 18 1M 15

17 Quality ratings results About 1/3 comments (34%) seeking to refine generalization Small difference in generalization comments counts between Arc and PDF formats (53 / 47% split)

18 Format Makes a Difference MO 250K enlarged ArcMap 120 ppi PDF 120 ppi

19 Resolution Makes a Difference ArcMap 91 ppi MO 250K enlarged ArcMap 120 ppi PDF 120 ppi

20 Example comments: Line symbol appearance, area generalization E/CO/100: line too narrow (flowlines); interference from other features above or below line (flowline, reservation, roads) E/UT/50: highway casings deteriorating due to pixelation; railway ticks not rendered evenly across line; intermittent stream dashes seem inconsistent due to rendering; river has jagged edge H/FL/500: areas too small to suit scale (waterbodies); too many area features (waterbodies); area shapes too complex (waterbodies) H/UT/500: Too many area features (reserve); Area shapes too complex (area hydro and incorp place); Areas too small to suit scale (NA reservation)

21 CO 1:100K C. Brewer, NationalMapping.us CEGIS, June 2011

22 UT 1:50K C. Brewer, NationalMapping.us CEGIS, June 2011

23 Example comments on Labels appearance/readability, positioning/generalization A/TX/250: Individual characters unaligned (e.g., county borders); letter forms jagged A/STL/24: Different case would better suit feature (change to lower case)(ems); Too large (ctr); Poor styling (EMS spacing too wide) B/ATL/50: some labels conflating with vector symbols underneath; some local road labels following roads too closely B/STL/50: Too many features of one type are labeled (schools); Difficult to understand location of named feature (EMS); Hierarchy of labels would better suit feature type (pop and incorp place)

24 TX 1:250K C. Brewer, NationalMapping.us CEGIS, June 2011

25 ATL 1:50K C. Brewer, NationalMapping.us CEGIS, June 2011

26 STL 1:50K C. Brewer, NationalMapping.us CEGIS, June 2011

27 Summary of Quality ratings Large majority of problems with rendering lines and labels, some of generalization of lines More issues in Arc than PDF Most issues noted at 100K, 250K and 500K Worst concentrations of issues in dense urban areas

28 Summary of Quality ratings - details Patterned and cased lines getting pixelated Hydro needing simplification at smaller scales Road labels often follow too closely, hydro labels too far Labels should have greater hierarchy and consistent use of case Some local roads need elimination at 100K Cluttering of labels at 100K in urban areas, sometimes hard to see association to features Some conflation between letter forms and linear symbols below them

29 Summary of Quality ratings - details Highway numbers overrunning shields/ovals, or not centered in them Vertical integration issues between hydro and admin areas (e.g., county borders) Intermittent streams too fine, hard to see Index contours hard to distinguish; contours not labeled often enough in general Too many points on map at 100K Hillshades sometime appear pixelated and grainy; require simplification other times

30 What s Next Refine design Refine hydro LoD 50K~200K (e.g., braiding, centerlines, islands) More hydro LoDs for 200K to 1M Generalize additional layers More categories of importance for pruning through scale (e.g., airports, populated places, local roads) Evaluate Preview of appearance for cached web display Attend to vertical data integration

31 Acknowledgements Funding: USGS Center of Excellence for Geospatial Information Science (CEGIS), 2007 to present funding Thanks to: babs buttenfield, CU Boulder Larry Stanislawski, Lynn Usery, Tom Hale, USGS-CEGIS Charlie Frye, ESRI Penn State Research Assistants: Paulo Raposo Chelsea Hanchett Andrew Stauffer