Cropping Graphics in a Macro

John often pastes screen shots into an Excel workbook. He invariably needs to crop these graphics on all four sides by a set amount. Because he does this task so often, he wonders if there is a way to do it easily in a macro.

There are a number of ways you can address this problem, and all of them involve the use of macros. (There are no built-in commands to do such a task.) If you simply want to crop a graphic you've already added, you can do so by using a simple macro such as this:

Sub CropPicture()
    With Selection.ShapeRange.PictureFormat
        .CropLeft = 200
        .CropTop = 300
        .CropBottom = 50
        .CropRight = 100
    End With
End Sub

You would, of course, need to specify the values for the cropping. These values are specified in points, and they are relative to the original size of the picture. So, for instance, if you previously scaled the selected picture to 150% of its original size, and then you run this macro, all of the crop settings will appear to be 1.5 times their actual values. (So, for instance, the left cropping would appear to be 300 pixels, not 200 pixels.)

The macro could easily be modified so that it does the pasting and then automatically crops the image. This is done by simply adding a single-line paste command:

Sub PasteCropPicture()
    ActiveSheet.Paste
    With Selection.ShapeRange.PictureFormat
        .CropLeft = 200
        .CropTop = 300
        .CropBottom = 50
        .CropRight = 100
    End With
End Sub

The macro assumes that you previously copied the screen shot to the Clipboard; if you try to run it without having done so, you may well get an error.

There is one other thing to remember when running a macro such as this: When it is done, it will appear that your image has moved from its original position in the worksheet. This occurs because cropping from all four sides will change the apparent upper-left corner of the image to a different location. You can, if desired, compensate for this in your macro by adding code that "remembers" the upper-left corner of the image:

Sub CropPositionPicture()
    Dim MyShape As Shape
    Dim LeftSide As Single
    Dim TopSide As Single

    Set MyShape = Selection.ShapeRange
    LeftSide = MyShape.Left
    TopSide = MyShape.Top

    With MyShape.PictureFormat
        .CropLeft = 200
        .CropTop = 300
        .CropBottom = 50
        .CropRight = 100
    End With

    MyShape.Left = LeftSide
    MyShape.Top = TopSide
End Sub

Of course, there is one thing to remember when you choose to crop graphics, regardless of how you choose to do so. Cropping doesn't affect image size. So, for instance, if you crop a screen shot so that only half of the screen is visible, all the "invisible" portions of the screen shot are still there, taking up space. This adds to the overall size of your workbook, sometimes amazingly so.

The only way around this is to not crop any graphics within Excel. Instead, process the image in a graphics program, save your processed image, and then insert that processed image in the worksheet. The result is smaller workbooks which means faster saving and loading.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (11580) applies to Microsoft Excel 2007, 2010, 2013, and 2016.