This Client Server article is republished in its entirety from 2004 for reference purposes.
By Bentley Technical Support Group08 March 2004
My HMR images are no longer displaying ever since I opened my MicroStation/J design file in MicroStation V8.
When I viewed my DGN file in MicroStation/J, the HMR images that had been attached with Image Manager displayed in the proper location. When I opened my DGN file in MicroStation V8, my images are listed in the Raster Manager dialog box, but they are not lining up with the existing line work.
Author's note: This work-around may not apply if a custom imgmngr.ini file was used or if the MicroStation V8 definition of working units has been modified.
The image disappears because MicroStation V8 uses the resolution in the MicroStation/J working units to define custom sub units. The HMR image location changes as a result of the working unit change. In the example below, the problem is not the design file working units, but rather in the way Image Manager hard codes the definitions for the working units when writing the image header.
The following conventions are used in this document to identify key components in the required calculations:
MicroStation/J and prior working unit abbreviations
MicroStation master unit name (label)
MicroStation sub unit name (label)
MicroStation sub unit to master unit of ratio
MicroStation positional unit resolution value
HMR INI file abbreviations
HMR INI file default master unit value
HMR INI file default sub unit value
Adjustment ratio abbreviations
Ratio of MicroStation custom "SU/MU" to a given HMR master unit
HMR image INI file master unit scale factor
HMR INI file adjusted sub unit
As a practical example, we will take a given MicroStation/J and prior design file with working units defined as:
When MicroStation V8 and higher imaging products encounter a MicroStation/J or prior design file with custom working units defined, the product will attempt to calculate an internal "SU/MU" ratio based on the following MicroStation/J and prior design file working unit fields:
The MicroStation V8 imaging products, by default, perform a lookup based on the unit labels within the appropriate configuration settings INI file (e.g.... \\imgmngr\imgmngr.ini). In the case of a MicroStation/J or prior design file with custom working units defined, the fields MU Name, "SU/MU", and SU Name will be referenced to determine the appropriate labels and "SU/MU" ratio to be applied.
Author's note: If the Unit Names are not populated, by default the blank value is defined the value of 1.
For this example:
Imgmngr.ini and working units
Note in particular the magnitude of difference between the HMRMU and HMRSU against which the HMR products process images. Compare them to the SU Name and MU Name of the MicroStation/J and prior design file custom working unit names. Also worth noting is that the decimal values used in the HMR INI file currently support a maximum of 17 significant digits of precision. You may optionally use scientific notation if high degrees of decimal accuracy need to be maintained.
MicroStation V8 and higher HMR imaging software apply the following calculation:
DGN2HMR = "SU/MU" * HMRSU
DGN2HMR = 10 * 0.0003047999999999
DGN2HMR = 0.003047999999999
To calculate the difference between the intended MicroStation/J and prior custom working units files and the actual HMR INI file definitions, we can use the following formula:
FX = DGN2HMR / HMRMU
FX = 0.003047999999999 / 0.30480000000000002
FX = 0.009999999999997
FXSU = HMRMU/""SU/MU""
HMR calculated "SU/MU" ratio = Default HMRMU definition value / MicroStation/J "SU/MU"
======================== = ===================== / ================
Sub Unit Def = (MU ini def) / (Res SU per MU)
0.030480000000000002 = 0.30480000000000002/10 / 10
If the Sub Unit Def is not in the HMR INI file the new definition will need to be added. In this case, because the sub unit def of 0.030480000000000002 does exist, we can use the predefined definition of "TN" or we can add a new entry with a unique two-character abbreviation.
To successfully apply the fix factor, the HMR image will need to be saved as a TIFF with a TFW (world file). The georeferencing for the TIFF image is saved in the TFW file, which is an ASCII file that contains the pixel size, rotation and origin of the image. The TIFF with TFW is the best format to use to fix this issue, since the world file default unit can be modified to fix the factor by which the image location is saved.
In the Image Manager dialog box select File> Batch Conversion
Select the HMR files you need to convert (please note, only convert HMR images that were created with the same working units)
Please note, this work-around is not applicable in builds of MicroStation /J or previous versions that have Raster Manager installed.
Client Server Archive
Raster Product TechNotes And FAQs
MicroStation Desktop TechNotes and FAQs
Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!