Out Of Memory With New Bitmap

The following code works with smaller images, but it throws an out of memory exception when the image is a png file, 8 bit depth, 13200x10234 pixels.

Using FS As New IO.FileStream(FileName, IO.FileMode.Open, IO.FileAccess.Read)
Dim B = New Bitmap(System.Drawing.Bitmap.FromStream(FS))
End Using

I'm working on a viewer that shows an image, asks the user for a window and saves the cropped image. Here is an overview of what I'm trying to achieve: The process starts with a 30+MB pdf file containing hundreds of large technical drawings. I open the file with the pdf reader, save as png 300dpi images, then I run my application that works on the saved images. I am interested on a few details of those drawings, and I have two goals:

1) Use my viewer with a subset of details instead of the pdf reader with the full set of whole images, and
2) Pick some cropped details and insert them into another application.

I start the application, look at the first image, click delete, and keep clicking delete until I find an drawing with a detail that I need. Then I draw a rectangle, save the cropped image, and repeat with 3-4 more details on the same image. Then delete the original image, go to the next, and restart the cycle. So I start with 100 large images in my folder and end with 20 small ones. At this point I can browse them very quickly and continue with the following steps (inserting them in another application).