Image Control Access 2002

T

Tom

Using an image control on a form and report with the image linked to that
control. The client is concerned about image quality. Would the client
experience any deteriation in image quality on the form or printed report
compared to the original image?

Thanks in advance for any advice


Tom
 
R

Randy

Tom said:
Using an image control on a form and report with the image linked to that
control. The client is concerned about image quality. Would the client
experience any deteriation in image quality on the form or printed report
compared to the original image?

Thanks in advance for any advice
Click to expand...

Tom, yes, there is an image quality issue when using an Access image control
linked (or embedded to a GIF, JPEG, PNG file). The quality and size are
lower or incorrect. There is no problems if the file is BMP thought.

That is Access 97. Any of these problems exist under Access 2000.

I also have experienced quality issues when dealing with 16-bit, 24-bit, and
32-bit colors (not with 256 color thought), but I cannot remember and I'm
actually unsure of the quality of testing procedure back a couple of years
ago.

If you are too concern (or you will use Access for client samples or
client-proofing material) please dedicate some time to run different tests
to make sure and avoid issues with the client.

-Randy
 
R

Randy

Randy wrote:

Rectifying myself: Any of those problems do NOT exist under Access 2000.
Tom, yes, there is an image quality issue when using an Access image
control linked (or embedded to a GIF, JPEG, PNG file). The quality and
size are lower or incorrect. There is no problems if the file is BMP
thought.

That is Access 97. Any of these problems exist under Access 2000.
Click to expand...

Any of these problems do NOT exist under Access 2000.
 
R

Randy

Stephen said:
I disagree with your statements Randy. I have worked extensively with
the standard Image control and all currently supported image formats.

If the Image control is sized to the dimensions of the original image,
SIzeMode is set to acOLESizeZoom, and the Graphics Adapter is set to
24bits or higher then there is no degradation of the original image. Any
issues with regards to ouput on reports are strictly Printer Driver
settings/capabilities.

--

HTH
Stephen Lebans
http://www.lebans.com
Access Code, Tips and Tricks
Please respond only to the newsgroups so everyone can benefit.
Click to expand...

Hi Stephen! As you I have also worked extensively with the Standard Image
Control (in both Access and Visual Basic) for about 8 years... I like
graphics ;-) Only in Access 97 I have personally experienced the abnormality
of getting a very low resolution and size when using this control for either
linking or embedding a GIF, JPEG, or PNG file. It has only proven to work
with a BMP file (at least on my side). Yes...the pictures were NOT set to
Zoom, nor Stretch. I first observed the issue back 2 years ago (as far as I
remember) on 3 different machines. Also I just tried now on my PC and I had
successfully replicated the issue.

It is important to keep in mind that there are different system components
and elements on different machines. In my case I got poor details and a
small picture size. It only works correctly when using a BMP file. That is
on Access 97. I have NOT experienced the issue using Access 2000.

Lets remember that there is always software issues that some (or most) of
the users will never experience. Perhaps somebody who had or currently have
this problem can share also their experiences as well.

Regards,

-Randy
 
R

Randy

Stephen said:
Again Randy, if you setup the control properly to match the dimensions
of the original image and set the SizeMode prop correctly, the issues
you describe will not appear. Unless your current Graphics adapter
settings are below 24 bit, Access 97 will display the image exactly the
same as in any other Office or Paint program.

#1
If you load a BMP or DIB Image, the Image control's PictureData prop
will contain a DIB. Access paints this directly onto the Form. Since the
DIB contains 8 bit RGB data, and if your current Graphics adapter
settings are set to 24bits( 8 bits for each RGB value) or higher, there
will be an exact representation of the original Image painted onto the
Form.

#2
For all other Image formats, the Image control's PictureData prop will
contain an Enhanced Metafile(or a WMF when loading WMF's). This EMF is
merely a wrapper for again, a DIB. All the rest of the issues for #1 now
apply.


There are some side issues as well that have to do with whether Access
uses its internal Image graphics filters of the standard Office Graphics
filters for certain image file formats. You can find further
documentation in the Image FAQ on my site.


The API call to resize the contents of an Image control are far better
in A97 for images that end up being stored as EMF's over DIB's. If I
remember correctly Access forgets to set the SetStretchBltMode to the
proper value before blitting the DIB to the form. The Metafile scaling
routines set the SetStretchBltMode to the proper value resulting in very
clean resized output.

THe resolution issue if more complex in its nature. Many Image file
formats do not store the resolution of the original image. Your monitor
is set to display at 96DPI(or 120DPI). What resolution do you want to
print the Image at. It all comes down to that if you know the dimensions
of the original image, you can load the image into the Image control and
be assured of an exact representation on the screen and in your report.


I certainly respect the issues you encountered on your system. I still
disagree with your statement that Access 97 can only display BMP files
correctly.

--

HTH
Stephen Lebans
http://www.lebans.com
Access Code, Tips and Tricks
Please respond only to the newsgroups so everyone can benefit.
Click to expand...

Stephen, That is correct. The Image Control fails in adjusting the graphic
when the Picture property is first initialized or updated. However I do
consider this to be an important observation, since any user needs to pick a
graphic file, and then be troubled (or clueless) about retrieving its
physical dimensions (from outside Access), converting both dimensions from
pixels to inches, and type them into the width and height properties, while
for BMP you don't have to. Very disturbing is to expect from a user to
behave this way, while the control should do this work (in fact, it does the
work in VB and Access 2000). Even worst, most likely the user will be
completely ignorant about these math and initialization steps, and will
proceed to change the Size Mode property, and then resizing the dimensions
of the objects by using mouse-n-eye approach, which it will result in either
incorrect picture-ratio and/or dimensions.

The issue doesn't bother me at all, and I was not complaining about it, but
I posted my experience, since I consider the Image Control's behavior
abnormal and relevant to what Tom was asking for feedback on issues of
apparent deterioration of image quality on forms and/or reports when using
this control. Worth to mention even more, since the behavior on the Image
Control is unique to Access 97, and it performs without inconveniences under
Access 2000 and Visual Basic.

I never stated that Microsoft's Image Control in Access could not display
GIF, JPG, or PNG files. It obviously does. I did say that there is an issue
on the control when using this type of files and not on BMP.

Thanks for your comments and all the data. I hope all the info helps Tom in
his concerns using the Image Control.

Regards,

-Randy
 
T

Tom

Thanks Randy & Stephen for all your input - I did not anticipate that it
would activate such a lively disscusion - but it certainly clarified points
for consideration

Tom
 
C

Christine Piereder

Stephen Lebans said:
Again Randy, if you setup the control properly to match the dimensions
of the original image and set the SizeMode prop correctly, the issues
you describe will not appear. Unless your current Graphics adapter
settings are below 24 bit, Access 97 will display the image exactly the
same as in any other Office or Paint program.

#1
If you load a BMP or DIB Image, the Image control's PictureData prop
will contain a DIB. Access paints this directly onto the Form. Since the
DIB contains 8 bit RGB data, and if your current Graphics adapter
settings are set to 24bits( 8 bits for each RGB value) or higher, there
will be an exact representation of the original Image painted onto the
Form.

#2
For all other Image formats, the Image control's PictureData prop will
contain an Enhanced Metafile(or a WMF when loading WMF's). This EMF is
merely a wrapper for again, a DIB. All the rest of the issues for #1 now
apply.


There are some side issues as well that have to do with whether Access
uses its internal Image graphics filters of the standard Office Graphics
filters for certain image file formats. You can find further
documentation in the Image FAQ on my site.


The API call to resize the contents of an Image control are far better
in A97 for images that end up being stored as EMF's over DIB's. If I
remember correctly Access forgets to set the SetStretchBltMode to the
proper value before blitting the DIB to the form. The Metafile scaling
routines set the SetStretchBltMode to the proper value resulting in very
clean resized output.

THe resolution issue if more complex in its nature. Many Image file
formats do not store the resolution of the original image. Your monitor
is set to display at 96DPI(or 120DPI). What resolution do you want to
print the Image at. It all comes down to that if you know the dimensions
of the original image, you can load the image into the Image control and
be assured of an exact representation on the screen and in your report.


I certainly respect the issues you encountered on your system. I still
disagree with your statement that Access 97 can only display BMP files
correctly.

--

HTH
Stephen Lebans
http://www.lebans.com
Access Code, Tips and Tricks
Please respond only to the newsgroups so everyone can benefit.
Click to expand...
 
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