ACC1x: Bitmap May Not Be Displayed Correctly
ID: Q95448
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The information in this article applies to:
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Microsoft Access versions 1.0, 1.1
SYMPTOMS
A bitmap that is displayed correctly in another application is not
displayed correctly in Microsoft Access.
CAUSE
When Microsoft Access starts, it loads a fixed 256-color palette. This
palette supports the most common colors used in bitmaps and metafiles. All
pictures and OLE Objects displayed in Microsoft Access are mapped to this
palette.
STATUS
This behavior is by design.
MORE INFORMATION
By using a fixed palette, Microsoft Access can display multiple pictures
and OLE Objects on the screen at one time without each new object affecting
the screen colors.
However, Microsoft Access can display multiple bitmaps at one time.
Therefore, because Windows can use only one palette at a time, Microsoft
Access uses a palette that usually is common to all the bitmaps Microsoft
Access might display.
That is why bitmaps and metafiles displayed in Microsoft Access may appear
to have a different color than when they are displayed in the application
in which they were created. Because Windows can use only one palette at a
time, each object Microsoft Access displays must be mapped to the fixed
color palette loaded by Microsoft Access. Microsoft Windows determines this
mapping. You cannot modify it.
Steps To Reproduce Behavior
- Start Microsoft Paintbrush (PBRUSH.EXE).
- Choose Image Attributes and select Black And White under the
Color option.
- Create a simple picture using several different shades of gray.
- Choose Save from the File menu.
- Under the Save File As Type option, select 256 Color Bitmap.
- Start Microsoft Access, and open the sample database NWIND.MDB.
- Open the Categories form in Form view.
- Select the Picture Control.
- Choose Insert Object from the Edit menu, and click the File button.
- Choose the file you just created in Microsoft Paintbrush, and click the
OK button. Note that the file loads as a solid black picture. Microsoft
Paintbrush uses a custom palette to offer a variety of shades of gray.
But Microsoft Access does not have the ability to load or reproduce
this custom color palette. Therefore, it requests that Windows map each
of the colors in the bitmap to the custom palette that was loaded when
Microsoft Access started.
This example is extreme. In most cases the color change will be slight.
Additional query words:
appearance graphic poor bad
Keywords : kbusage FmrColr
Version : 1.0 1.1
Platform : WINDOWS
Issue type : kbprb