Raster images load very slowly

Question

Hello, 
 I am trying to attach multiple raster images totaling around 1 GB of data. The rasters are aerial images that were taken from NearMaps. I am having trouble with how slowly the rasters are loading. It can take up to 15 minutes for a few rasters to load, and I have never gotten all of the rasters to load (50 images) at the same time. 
 Does anyone have any suggestions on how I can get these aerials to load faster? 
 Thanks in advance.

Andrew Bell · Answer

You can improve the performance of raster handling within MicroStation by specifying the location to store cached files. This can be achieved by using both MicroStation and Windows variables. You can control where MicroStation caching is performed locally by creating a Windows variable called HMRTempDirectory. You can use this variable to define a specific location on your hard disk where caching is performed. To achieve this, firstly create a local directory (eg C:\RasterCache\). Then, from your desktop right click on the &lsquo;My Computer&rsquo; icon and select &lsquo;Properties.&rsquo; From the &lsquo;Advanced&rsquo; tab, select &lsquo;Environment Variables.&rsquo; Create a new variable called &lsquo;HMRTempDirectory&rsquo; and define the location to the previously created location. 
 
 Within MicroStation you should then also create the configuration variable MS_RASTER_LOADMODE with a value of 3. Within MicroStation, go to the Workspace>Configuration menu and select &lsquo;New&rsquo; to create the variable. This will ensure that the caching is performed in the defined location. This information can be found and explained in further detail by TechNote 6205 on Select Services. 
 
 http://communities.bentley.com/products/microstation/w/microstation__wiki/attaching-displaying-raster-images-in-microstation-cs.aspx

Lorys · Answer

have you created a holding file and attached all the rasters to it then use this holding file as a reference file with the ref manager... 
 Another trick is to convert the jpgs to .TIFF ( georeferenced) via the raster manager then make new holding file and reattach the geo tiffs no sister files needed... I chose the no loss uncompressed option... seems to load faster for me.. 
 another option from old school days still works well 
 create a map grid by attach one raster at a time, then trace its edges on a non print level and type in the name of the jpg as text inside the tile, turn off and proceed with next jpg untill all are mapped.. now you can use this as a grid or tile index and work out what jps to use or just have all turned off when attached as xref and use the raster manager to only turn on the tiles you actually need turn on... 
 one more option... look up package to join all the rasters together and let it join all the tiles together as one raster , this them loads faster for me than lots of little ones I dont get why but it does for me... 
 I use AU_ECW compressor 
 To compress one image file To compress several image files of the same size and shape into one file To add geo-referencing to an image file 
 no longer available.. web site gone, was free .. I have it installed but I dont have the install file any more... 
 Ok more digging around and found you can do it in GDAL but its not gui driven so hard to learn best next option is QGIS free gis can combine some geo ref rasters into one merged raster.. 
 http://www.qgistutorials.com/en/docs/raster_mosaicing_and_clipping.html

Tim Hickman · Answer

Have you tried OpenRoads or MicroStation CONNECT ? The reason I ask is that there is an option to turn on a background map.

Tim Hickman · Answer

here is an old post - now you no longer need to obtain a bing maps license 
 https://communities.bentley.com/products/microstation/b/microstation_blog/posts/bing-maps-in-microstation