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spetric
Croatia
308 Posts |
 Posted - Jan 25 2019 : 09:34:12
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Hi,
I'm trying to set and fill alpha channel for TIEBitmap in TImageEnMView, but it does not work (it worked only on some specific png image - without alpha channel) :
mView->SetImage(0, ienIO->IEBitmap);
TIEBitmap *map = mView->GetTIEBitmap(0, true);
if (!map->HasAlphaChannel)
map->AlphaChannel->Fill(255);
mView->ReleaseBitmap(0, true);
When such map is recalled:
TIEBitmap *map0 = mView->GetTIEBitmap(0, true);
alpha channel of map0 is NULL.
So, the question is how to add alpha channel to TIEBitmap contained in
TImageEnMView?
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xequte
38610 Posts |
Posted - Jan 25 2019 : 19:59:42
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Hi Sinisa
Do you mean map0->AlphaChannel is NULL? ImageEn should create the AlphaChannel if it does not exist in this case.
Nigel
Xequte Software
www.imageen.com
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spetric
Croatia
308 Posts |
Posted - Jan 26 2019 : 14:36:21
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Hi Nigel,
Exactly. I don't know what I'm doing wrong.
Here is how I set alpha chanel in ImageEnMView:
//---------------------------------------------------------------------------
void __fastcall TForm1::btnLoadMasterClick(TObject *Sender)
{
if (openDialog->Execute())
{
ienIO->LoadFromFile(openDialog->FileName);
// delete additinal images
while (mView->ImageCount > 2)
mView->DeleteImage(mView->ImageCount - 1);
// append or insert image
if (mView->ImageCount == 0)
{
// test
//if (!ienIO->IEBitmap->HasAlphaChannel)
// ienIO->IEBitmap->AlphaChannel->Fill(255);
mView->InsertImage(0);
mView->SetImage(0, ienIO->IEBitmap);
mView->ImageTopText[0] = "master";
}
else
mView->SetImage(0, ienIO->IEBitmap);
TIEBitmap *map = mView->GetTIEBitmap(0, true);
if (!map->HasAlphaChannel)
map->AlphaChannel->Fill(255);
mView->ReleaseBitmap(0, true);
ieView->SetExternalBitmap(mView->IEBitmap);
}
}
When I recall the image again, here is what I get:
As you can see map0->AlphaChannel is NULL (line 106).
Of course, when code at line 107 is executed it will create new alpha channel.
Actually, every time I execute this piece of code, alpha channel is recreated...at least I think so.
Update: This problem with alpha channel never occurs with ImageEnView or ImageEnVect IEBitmap. But, at least I discovered that I misspelled Hamming and wrote Humming :)
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xequte
38610 Posts |
Posted - Jan 27 2019 : 17:22:40
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Hi Sinisa
Can you please attach your test image.
Nigel
Xequte Software
www.imageen.com
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spetric
Croatia
308 Posts |
Posted - Jan 28 2019 : 04:05:10
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Hi Nigel,
Any loaded jpg image will behave the same. If loaded image already has
alpha channel (png) it will work ok.
I've added few test lines when loading image:
if (openDialog->Execute())
{
ienIO->LoadFromFile(openDialog->FileName);
// delete additinal images
while (mView->ImageCount > 2)
mView->DeleteImage(mView->ImageCount - 1);
// append or insert image
if (mView->ImageCount == 0)
{
// test
//if (!ienIO->IEBitmap->HasAlphaChannel)
// ienIO->IEBitmap->AlphaChannel->Fill(255);
mView->InsertImage(0);
mView->SetImage(0, ienIO->IEBitmap);
mView->ImageTopText[0] = "master";
}
else
mView->SetImage(0, ienIO->IEBitmap);
TIEBitmap *map = mView->GetTIEBitmap(0, true);
if (!map->HasAlphaChannel)
map->AlphaChannel->Fill(255); // alpha channel created
mView->ReleaseBitmap(0, true);
// check image again
map = mView->GetTIEBitmap(0, true); // alpha channel is null
mView->ReleaseBitmap(0, true);
ieView->SetExternalBitmap(mView->IEBitmap);
}
Here are two images attached (jpg and png). Jpg does not have alpha channel and
I can not add alpha channel in ImageEnMView.
attach/spetric/2019128452_f2d_test.zip
450.71 KB |
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xequte
38610 Posts |
Posted - Jan 29 2019 : 16:00:42
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Thanks for the detail.
Actually, ImageEn is seeing that the Alpha channel contains no Alpha, so when you retrieve it the second time, it discards the alpha channel.
It works if you either:
- Fill Alpha channel with <255 value
- Set map.AlphaChannel.Full := False;
Sorry for the confusion.
var
map: TIEBitmap;
begin
ienIO.LoadFromFile( IEAddBackslash( ExtractFilePath( Application.ExeName )) + 'image.jpg' );
// delete additinal images
while (mView.ImageCount > 2) do
mView.DeleteImage(mView.ImageCount - 1);
// append or insert image
if (mView.ImageCount = 0) then
begin
// test
//if (!ienIO.IEBitmap.HasAlphaChannel)
// ienIO.IEBitmap.AlphaChannel.Fill(255);
mView.InsertImage(0);
mView.SetImage(0, ienIO.IEBitmap);
mView.ImageTopText[0] := 'master';
end
else
mView.SetImage(0, ienIO.IEBitmap);
map := mView.GetTIEBitmap(0, true);
if (not map.HasAlphaChannel) then
map.AlphaChannel.Fill(125)
if (not map.HasAlphaChannel) then
ShowMessage( 'no alpha channel');
mView.ReleaseBitmap(0, true);
// check image again
map := mView.GetTIEBitmap(0, true);
if (not map.HasAlphaChannel) then
ShowMessage( 'no alpha channel');
mView.ReleaseBitmap(0, true);
end;
Nigel
Xequte Software
www.imageen.com
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spetric
Croatia
308 Posts |
Posted - Jan 31 2019 : 02:42:01
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Hi Nigel,
Thanks for info.
So, when using ImageEnMView, I can not set all alpha channel pixels to max value (255)?
This is very strange.
I need all alpha pixels to max value (for images without alpha channel), because in the next step image is transformed (perspective warping and resizing - new image) together with alpha channel (I'm using OpenCV 4.0 for that):
if (outImage)
{
Size size = imgSample.size();
// warp and align to sample using homography matrix
warpPerspective(imgMaster, imgReg, homography, size);
if (alphaMaster.empty())
alphaReg = Mat();
else // warp alpha channel and align to sample
warpPerspective(alphaMaster, alphaReg, homography, size);
}
else
imgReg = Mat();
Of course, prior to transformation function, I can create alpha channel (if it does not exists) and fill it with 255 (it works), or I can set one pixel to 244 when image is loaded. I prefer setting alpha channel once the image is loaded...but setting one pixel value to 244 looks like a brute hack.
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xequte
38610 Posts |
Posted - Jan 31 2019 : 15:23:14
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Hi Sinisa
Hmmm, let me discuss this with my partner.
In the meantime, you should just be able to use:
if (!map->HasAlphaChannel)
{
map->AlphaChannel->Fill(255); // alpha channel created
map->AlphaChannel->Full = FALSE; // Force ImageEn to keep alpha channel
}
Nigel
Xequte Software
www.imageen.com
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spetric
Croatia
308 Posts |
Posted - Jan 31 2019 : 16:41:00
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Hi Nigel,
Setting Full to false did the job.
I've put this line when loading the image:
if (openDialog->Execute())
{
ienIO->LoadFromFile(openDialog->FileName);
while (mView->ImageCount > 2)
mView->DeleteImage(mView->ImageCount - 1);
if (mView->ImageCount == 0)
{
if (!ienIO->IEBitmap->HasAlphaChannel)
{
ienIO->IEBitmap->AlphaChannel->Fill(255);
ienIO->IEBitmap->AlphaChannel->Full = false;
}
mView->InsertImage(0);
mView->SetImage(0, ienIO->IEBitmap);
mView->ImageTopText[0] = "master";
}
else
mView->SetImage(0, ienIO->IEBitmap);
ieView->SetExternalBitmap(mView->IEBitmap);
}
Thanks a lot,
Siniša
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xequte
38610 Posts |
Posted - Feb 01 2019 : 04:18:28
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Hi Sinisa
For the next release, we've decided it should return the alpha channel even when it is full.
Nigel
Xequte Software
www.imageen.com
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TImageEnMView alpha channel
