Bitmap manipulation from VBA/VB

I am needing to load a bitmap, then run through some code that would
transform the image by looking at each pixel's color and if the RGB is less
than 10,10,10 then change the pixel to some other color. How do I do this?
Is there some kind of object I can use that will allow changing this from
VB/VBA?

--
Regards,
John

You can do this if you use Windows API functions; here is a reference for the
Bitmap functions (note in particular GetBitmapDimensionEx and
GetPixel/SetPixel):
http://msdn.microsoft.com/library/de...tmaps_87eb.asp
If you are not familiar with using API library functions you may want to
search the MSDN libarary on the topic.
--
- K Dales


"John Keith" wrote:

> I am needing to load a bitmap, then run through some code that would
> transform the image by looking at each pixel's color and if the RGB is less
> than 10,10,10 then change the pixel to some other color. How do I do this?
> Is there some kind of object I can use that will allow changing this from
> VB/VBA?
>
> --
> Regards,
> John

I followed the link for the API calls. I found some more info on how to use
API from VBA (see link below). I am still confused on how the API calls will
relate to the VBA code......
ActiveSheet.Pictures.Insert( _
"C:\Documents and Settings\JKeith\My Documents\My Pictures\test.bmp" _
).Select
Selection.ShapeRange.IncrementLeft 108
Selection.ShapeRange.IncrementTop 91.5
Selection.ShapeRange.IncrementRotation 60
Selection.ShapeRange.ScaleHeight 0.65, msoFalse, msoScaleFromTopLeft
Selection.ShapeRange.ScaleWidth 0.65, msoFalse, msoScaleFromTopLeft

Do the API calls for SetPixel directly change the BMP file? (so I would do
all the API calls before I "insert" the picture into the spreadsheet?)

Is there some way to assign the API picture handle to the pictures.insert?
or will this have to be done externally?

For anyone that is looking to find out how to call API from VBA.... (this
link is for you)
http://www.awprofessional.com/articl...?p=366892&rl=1

--
Regards,
John


"K Dales" wrote:

> You can do this if you use Windows API functions; here is a reference for the
> Bitmap functions (note in particular GetBitmapDimensionEx and
> GetPixel/SetPixel):
> http://msdn.microsoft.com/library/de...tmaps_87eb.asp
> If you are not familiar with using API library functions you may want to
> search the MSDN libarary on the topic.
> --
> - K Dales
>
>
> "John Keith" wrote:
>
> > I am needing to load a bitmap, then run through some code that would
> > transform the image by looking at each pixel's color and if the RGB is less
> > than 10,10,10 then change the pixel to some other color. How do I do this?
> > Is there some kind of object I can use that will allow changing this from
> > VB/VBA?
> >
> > --
> > Regards,
> > John

For an unrefined but effective solution, see http://zababcdblog.blogspot.com/2012...excel-vba.html and the improvement at http://zababcdblog.blogspot.com/2012...cel-vba-2.html

In my defence, my goal was to share my solution, not for 'my blog's SEO' but because I didn't see my solution when I was looking for it, so I thought I would provide it for anyone else who was looking for it. I searched for people with this problem and provided my solution for them. I failed to check when the question was asked, and will do so in any future posts.

I just wanted to put in a humble request to teylyn - hopefully I'm not overstepping bounds! Zababcd's post was very helpful to me, and I personally appreciate that (he?) updated the thread. I just wanted to let you both know that it was helpful (thanks Zab), and wonder if instead posts like this could be accepted... unless the poster can be re-directed to a more recent version of the question. I'm in agreement with Zababcd's philosophy, the idea that a thread is closed once a solution is found, and hope teylyn will reconsider your position.

Leith Ross said, "There is a policy in place here at the forum so members can share their thoughts and solutions about older posts."

I registered partly to say that I like this policy, and often find use from replies that are several years after the original post. I appreciate when someone does add a new solution to an old problem. It is especially useful for a program like Excel which evolves over time, as does the operating system, and what people use it for.

The Zababcd blog is gone, so those links don't work. Part of the code can be found at another forum.

The idea is to load an image into an array, and then use the array data to create an image.

I found some other interesting takes on this. Daniel Pineault discusses resizing an image in VBA using the Microsoft Windows Image Acquisition (WIA) interface and also using using FreeImage. The latter does include some source code that he charges for, but FreeImage (of course) is free.

FreeImage is a great lead, since it includes wrapper modules that work with almost anything.

It says it can "directly access bitmap bits and palette."

"Functions are provided which allow you to directly access the bitmap palette (if available) and bitmap bits."

The wrappers work with Visual Basic as well as with any Component Object Model (COM) aware development environment (which includes VBA). It would be nice if it included VBA source code, but this is the next best thing.

For that matter, other tools that can talk to COM would work. I've used AutoHotkey to talk to the Excel COM. Something like that might be hackish, but if you had to, you could use an outside tool to take a graphic from Excel, manipulate it, and then send it back in.

There is also a library of games written for Excel. No doubt some of them use innovative ways to manipulate graphics.

And finally, don't forget that you can draw lines and shapes even onto say a userform. That might be of use for some types of graphic manipulation.

Anyway, these Excel resources on the web are very useful and there is a lot of good help available. So thank you for your contributions!

Dan