Changing the size of an image

[Geometrical]

Here a detailed tutorial on how to successfully resize an image.



●First of all you do not do this:

John has an image with the dimensions 300 x 200 and he wants to increase each by 100. He loads an image into a picturebox and does the following:

PictureBox1.Size = New Size(400, 300)
PictureBox1.Image.Save("Cute Dog.png")

It will not work since the save functions saves the image as it is and also John does not know Visual Basic.

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And now lets get to what you should do.

●First of all we need to import namespace 'Drawing' which has some handy elements such as classes, functions etc.

Imports System.Drawing

●Now lets create the function that will resize the image you want with the the original image and the new size as input.

Function ResizeImage(Byval Image As Image, Byval NewSize As Size) As Image

●Create a new blank bitmap.

Dim _Image As Image = New Bitmap(NewSize)

●Now create the graphics handle to the image.

Dim _Graphics As Graphics = Graphics.FromImage(_Image)

●Now we draw the original image onto to the blank bitmap using the handle.

_Graphics.DrawImage(Image, 0, 0, Size.Width, Size.Height)

●Now to end the function.

End Function

●Heres the code in actions:

You have an image of 400 x 50 and want to change the dimensions to 200 x 50. So heres what you can do:

PictureBox1.Image = ResizeImage(My.Resources.MyImage, New Size(200 x 50))
PictureBox1.Imge.Save("Cute Dog.png")

And thats all.

[abuckau907]

Don't forget to call

_Graphics.Dispose()

and ofc

Return _Image

Thnx for sharing.

[Geometrical]

Don't forget to call

_Graphics.Dispose()

and ofc

Return _Image

Thnx for sharing.

Oh yes, thx for reminding. And also add on:

CompositingQuality = CompositingQuality.HighQualityBicubic

For a better result on the output.