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Hi,
I way trying to change the opacity of one bitmap by using the following code
Dim image as New Aurigma.GrphicMaill.Bitmap("C:\mypic.jpg")
Dim TransBitmap As New Aurigma.GraphicsMill.Bitmap(image.Width, image.Height, Aurigma.GraphicsMill.PixelFormat.Format32bppArgb)
image.Draw(TransBitmap, 0, 0, image.Width, image.Height, Aurigma.GraphicsMill.Transforms.CombineMode.Alpha, 0.3F, Aurigma.GraphicsMill.Transforms.InterpolationMode.HighQuality)
What I would like to do is load this semi transparent image into VObject so that it could be use in the multilayer viewer.
but seems like it doesn't work. Anyone could help out with this please?
Thanks.
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Hi, Current implementation of the Graphics Mill for .NET doesn't change alpha channel of the destination bitmap, so you cannot perform this with Bitmap.Draw(...) method. But! ;) If you are loading image without alpha channel and want to create partially-transparent image you can do this that way: Code:
Dim image As New Aurigma.GraphicsMill.Bitmap("x:\allformats\24bppRgb.jpg")
image.Channels.AddAlpha(0.7)
Best wishes, Alex.
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Alex Kon wrote:Hi, Current implementation of the Graphics Mill for .NET doesn't change alpha channel of the destination bitmap, so you cannot perform this with Bitmap.Draw(...) method. But! ;) If you are loading image without alpha channel and want to create partially-transparent image you can do this that way: Code:
Dim image As New Aurigma.GraphicsMill.Bitmap("x:\allformats\24bppRgb.jpg")
image.Channels.AddAlpha(0.7)
Cool.. But is there any way to detect the Alpha Value from a bitmap? Please advice. Regards
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Hello,
What do you mean by phrase "detect the Alpha Value"? If you want to determine whether bitmap has alpha channel or not - you may use Bitmap.HasAlpha property. Or you mean something else?
Best wishes, Alex.
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Alex Kon wrote:Hello,
What do you mean by phrase "detect the Alpha Value"? If you want to determine whether bitmap has alpha channel or not - you may use Bitmap.HasAlpha property. Or you mean something else?
What I want to know is the value we set for the Alpha (example 0.7F)
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Hello, You can read any bitmap's pixel color and check the alpha value. Of course, if you sure that alphas of all pixels are the same (e.g. if you set it by Bitmap.Channels.AddAlpha(...) call). You can use Bitmap.GetPixel(...) method to read color value.
Best wishes, Alex.
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Alex Kon wrote:Hello, You can read any bitmap's pixel color and check the alpha value. Of course, if you sure that alphas of all pixels are the same (e.g. if you set it by Bitmap.Channels.AddAlpha(...) call). You can use Bitmap.GetPixel(...) method to read color value. Hi, Thanks.... But, for unknown reason, the getPixel only work once Public Function getAlphaValue(ByVal backgroundImage As Aurigma.GraphicsMill.Bitmap) As Double Dim _color As System.Drawing.Color Dim dblRet As Double = 1 Dim myBitmap As Aurigma.GraphicsMill.Bitmap Try myBitmap = CType(backgroundImage, Aurigma.GraphicsMill.Bitmap) _color = myBitmap.GetPixel(10, 10) dblRet = _color.A / 255 Catch ex As Exception Finally dblRet = dblRet * 100 End Try Return dblRet End Function I had a function as above, while, the backgroundImage will be called from a VObject.tag It works fine while I am working on it. While I save the file (serialized the .tag, and deserialized the bitmap back to the vobject.tag) then @ this line _color = myBitmap.GetPixel(10, 10) I will get the err.Description of "Object reference not set to an instance of an object." Please advice.
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Hello, We confirm the issue with Bitmap.GetPixel() method after object's deserialization. If this is critical for you, please submit case.
Best wishes, Alex.
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beside getPixel, is there any alternative way to get the Alpha Value of the image?
Please advice.
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Hello, Yeap, here is workaround code: Code:
Aurigma.GraphicsMill.Bitmap image =
new Aurigma.GraphicsMill.Bitmap("x:/allformats/24bppRgb.jpg");
image.Channels.AddAlpha(0.5f);
Aurigma.GraphicsMill.BitmapData imageData = image.LockBits(0, 0, 1, 1);
try
{
Aurigma.GraphicsMill.RgbColor pixColor =
(Aurigma.GraphicsMill.RgbColor)imageData.GetPixel(0, 0);
System.Windows.Forms.MessageBox.Show(pixColor.ToString());
}
finally
{
image.UnlockBits(imageData);
}
Best wishes, Alex.
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Alex Kon wrote:Hello, Yeap, here is workaround code: Code:
Aurigma.GraphicsMill.Bitmap image =
new Aurigma.GraphicsMill.Bitmap("x:/allformats/24bppRgb.jpg");
image.Channels.AddAlpha(0.5f);
Aurigma.GraphicsMill.BitmapData imageData = image.LockBits(0, 0, 1, 1);
try
{
Aurigma.GraphicsMill.RgbColor pixColor =
(Aurigma.GraphicsMill.RgbColor)imageData.GetPixel(0, 0);
System.Windows.Forms.MessageBox.Show(pixColor.ToString());
}
finally
{
image.UnlockBits(imageData);
}
Hi, Seems like the issue is still there. It will still goes into same error message on Aurigma.GraphicsMill.RgbColor pixColor = (Aurigma.GraphicsMill.RgbColor)imageData.GetPixel(0, 0);
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Hello, Its very strange! Which version of Graphics Mill for .NET do you use? Here is full code of my test application: Code:
Aurigma.GraphicsMill.Bitmap image =
new Aurigma.GraphicsMill.Bitmap("x:/allformats/24bppRgb.jpg");
image.Channels.AddAlpha(0.5f);
System.IO.FileStream fs =
new System.IO.FileStream("y:/data.dat", System.IO.FileMode.Create);
image.Serialize(fs);
image.Dispose();
image = new Aurigma.GraphicsMill.Bitmap();
fs = new System.IO.FileStream("y:/data.dat", System.IO.FileMode.Open);
image.Deserialize(fs);
fs.Close();
Aurigma.GraphicsMill.BitmapData imageData = image.LockBits(10, 10, 1, 1);
try
{
Aurigma.GraphicsMill.RgbColor pixColor =
(Aurigma.GraphicsMill.RgbColor)imageData.GetPixel(0, 0);
System.Windows.Forms.MessageBox.Show(pixColor.ToString());
}
finally
{
image.UnlockBits(imageData);
}
Could you test this sample and let me know whether the issue can be reproduced on your machine?
Best wishes, Alex.
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Code:
Public Function getAlphaValue(ByVal backgroundImage As Aurigma.GraphicsMill.Bitmap) As Double
Dim _color As System.Drawing.Color
Dim dblRet As Double = 1
Dim imageData As Aurigma.GraphicsMill.BitmapData = backgroundImage.LockBits(0, 0, 1, 1)
Try
_color = backgroundImage.GetPixel(0, 0)
dblRet = _color.A / 255
Catch ex As Exception
Finally
backgroundImage.UnlockBits(imageData)
dblRet = dblRet * 100
End Try
Return dblRet
End Function
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Hello,
You should call GetPixel(...) method of the Aurigma.GraphicsMill.BitmapData class, not Aurigma.GraphicsMill.Bitmap one. Please, look at the code sample I've posted above.
Best wishes, Alex.
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