Transparency proble in drawing PNG file.

[prajapatmanoj]

Hello
I am developing an application using S60 3rd Editon FP1.
I am having problem in drawing of PNG image. I performed following two things:
Conversion of PNG into MBM
What I did is converted the PNG file in MBM file using the Image Converter Library. Using conversion library I created the MBM represantation and mask file of given PGN file. Both the MBM are created successfuly and correctly. I checked them by drawing them in the draw() function of the CCoeControl class using the DrawBitmap(). Both, the image and its mask are created properly.

Drawing the converted Image
Problem is that when I try to draw it using BitBltMasked() the image is not showing transparency. I did following in the Draw()function of CCoeControl:
1. Set brush color to white
2. draw a background image using BitBltMasked()function.
3. draw the png image over this background image using BitBltMasked()function.

Now the problem is that the transparent area of the image is showing me white color instead of the image drawn in the second step. What I am doing wrong. Please guide.

Thanks

[wizard_hu_]

The brush is the evil. BitBltMasked uses the brush for transparent regions, set ENullBrush prior to BitBltMasked, and your problem will probably be gone.

[prajapatmanoj]

Thanks wizard_hu_ !!!!
It worked and now images are drawing properly.
Thanks for your quick response.

[coolblues5000]

Hi

how did you convert the PNG to MBM?

[yogpan]

Hi,
You can use ICL to make MBM out of png file
To know more about the ICL check this wiki link
http://wiki.forum.nokia.com/index.ph...rary_%28ICL%29

[coolblues5000]

Hi,
You can use ICL to make MBM out of png file
To know more about the ICL check this wiki link
http://wiki.forum.nokia.com/index.ph...rary_%28ICL%29

i copy pasted the Image_Reader.cpp and Image_Reader.h to my project.. it isn't working. there are build errors.

unidentified identifier aResult

[Sorcery-ltd]

The image reader example in the wiki doesn't contain "aResult" so it's probably somewhere else in your code.

EDIT: Sorry, yes it does. Looks like a mistake in the wiki code:

if(FileDataType.iConfidence > aResult.iConfidence)
    {
    aFileType.Copy(FileDataType.iDataType.Des8());
    }

You could just take the check out but it might be better to find a confidence level to compare against.

Sorcery

[Kavit Patel]

I think commenting aResult.iConfidence will not make any problem in conversion.

Means..

if(FileDataType.iConfidence)// > aResult.iConfidence)
    {
    aFileType.Copy(FileDataType.iDataType.Des8());
    }

will be enough.

Regards,
Kavit.

[coolblues5000]

I see. I will try this again. I'm new to Symbian c++. its very confusing.... haha

[Sorcery-ltd]

Yes, like I said, you can take the check out. It might be better to compare it to one of the pre-defined constants though. I added a comment to the wiki article.

Sorcery

[coolblues5000]

i fixed the build error. my problem is how do i use this? do i nid to place CImage_Reader a;
then

a.ConstructL(_L("sample.png"));???

-- edit --

sorry. i didn't include the Image_Reader in my .mmp, when i included the Image_Reader 100 errors occurred...