Difference Between Bitmap and Picture When Using Paste Special

Bitmap Definition

A bitmap is a block of data that describes a rectangular region on a pixel by pixel basis. In the simplest case, the size of a bitmap is dependent on the number of colors it contains (Monochrome, 16 color, 256 color, 24 bit), and its physical dimensions. Typically, the actual image that the bitmap represents has very little to do with the size and/or complexity of a bitmap data structure. A disadvantage of purely bitmap images are that they cannot be scaled or resized without losing some of the quality of the image (dithering, jaggedness, and other distortion).

Pictures (Metafiles)

Pictures (metafiles) typically consist of many different data structures. These structures can include bitmaps and other types of objects. If the types of objects are described by the commands necessary to render them (that is, GDI function calls), very little memory will be used to represent a very complex image. Another advantage of Pictures is that they can generally be resized and printed to a variety of devices at the highest resolution supported by those output devices.


Because a picture can contain a combination of data types, if one of the data types included is a bitmap, then scaling/resizing of the picture will result in the same kinds of distortion (of only the bitmap element) that you would expect if you were to simply scale/resize the bitmap by itself. For example, if the object was copied from Paintbrush to the Clipboard, then there is not much difference between the Picture format and the Bitmap format listed in the Paste Special dialog box. However, if the object was copied from an application that typically deals with metafiles such as Microsoft Excel for Windows, the difference between pasting a Picture and a Bitmap from that application could be quite significant.

File Size Difference Between Bitmaps and Pictures

Follow this procedure to see the file size difference between a bitmap and a picture (metafile):

1. Load version 3.0 or 4.0 of Microsoft Excel for Windows.
   
2. Load a spreadsheet in Excel.
   
3. Copy the spreadsheet to the Clipboard.
   
4. Run Microsoft Write.
   
5. From the Edit menu, choose Paste Special.
   
6. From the Paste Special dialog box, select Bitmap.
   
7. Choose the Paste button.
   
8. Save the Write file as BITMAP.WRI.
   
9. From the File menu, choose New.
   
10. From the Edit menu, choose Paste Special.
    
11. From the Paste Special dialog box, select Picture.
    
12. Choose the Paste button.
    
13. Save the Write file as META.WRI.
    

Compare the file sizes of META.WRI and BITMAP.WRI in File Manager; BITMAP.WRI should be larger than META.WRI.

KBCategory: kbusage kbgraphic
KBSubcategory: win31