CODEWITHSUNDEEP
vb.netimage-manipulation
Cyclone
Cyclone

Reputation: 18295

Convert image format from .bmp to other image formats in vb.net

How do you convert a System.Drawing.Bitmap image to another type of image? I tried CType, which failed, since I do not know the type for .png or .jpg. I cannot find it anywhere on google either.

What is the most efficient method to do this while keeping the quality of the image as high as possible?

Upvotes: 7

Views: 14374

Answers (3)

Sherbet
Sherbet

Reputation: 71

Here is how to convert an image type without saving to a file in VB.NET You might also be able to port this into C#, but I haven't tested that.

Public Function ConvertImageType(Image As Bitmap, Format As 
    Drawing.Imaging.ImageFormat) As Byte()
        'Declare a new memory stream to write to
        Dim SaveStream As New IO.MemoryStream
        'Save the bitmap/image to the memory stream in the desired format
        Image.Save(SaveStream, Format)
        'Extract the file bytes from the memory stream
        Dim ConvertedImageBytes() As Byte = SaveStream.ToArray
        'Return bytes to caller
        Return ConvertedImageBytes
    End Function

This method can convert a Bitmap/Image type to the following formats: Jpeg, Png, Bmp, Ico, Gif, Emf, Exif, Tiff and Wmf.

Upvotes: 1

Charlie Salts
Charlie Salts

Reputation: 13488

Check out the Drawing.Bitmap.Save() method. I recommend saving as PNG - it's lossless and achieves reasonable compression. See the Imaging.ImageFormat enum - this is how you specify the image type you want.

Upvotes: 3

Kibbee
Kibbee

Reputation: 66122

The system.Drawing.Bitmap class can handle opening and saving any kind of bitmap image, including JPG, PNG, GIF, BMP, and others.

To save an already opened file as a different format you can use the save method as so

MyImage.Save("ImageName.jpg",System.Drawing.Imaging.ImageFormat.Jpeg)

The class name of Bitmp refers more specifically to the general concept of storing a picture as a series of coloured pixels rather then the actual format of BMP, which is one possible way to store the representation of the pixels that make up an image.

Upvotes: 9

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