The Microsoft Excel File Format - OpenOffice.org

5.5 BACKUP
5.5 BACKUP
BIFF2 BIFF3 BIFF4 BIFF5 BIFF8
0040 H 0040 H 0040 H 0040 H 0040 H
This record contains a Boolean value determining whether Excel makes a backup of the file while saving.
Record BACKUP, BIFF2-BIFF8:
Offset Size Contents
0 2 1 = Create a backup on saving
5.6 BITMAP
BIFF2 BIFF3 BIFF4 BIFF5 BIFF8
— — — — 00E9 H
This record is part of the Page Settings Block (➜4.4). It stores the background bitmap of a worksheet.
Record BITMAP, BIFF8:
Offset Size Contents
0 2 Unknown value 0009 H
2 2 Unknown value 0001 H
4 4 Total size of the following record data, without this field (including CONTINUE records)
8 2 Unknown value 000C H
10 2 Unknown value 0000 H
12 2 Width of the picture (width), in pixel
14 2 Height of the picture (height), in pixel
16 2 Number of planes, must be 0001 H
18 2 Colour depth, must be 0018 H (24 bit true-colour)
20 var. Pixel data (array of height lines of the bitmap, from bottom line to top line, see below)
In each line all pixels are written from left to right. Each pixel is stored as 3-byte array: the red, green, and blue
component of the colour of the pixel, in this order. The size of each line is aligned to multiples of 4 by inserting zero
bytes after the last pixel.
Example of the bitmap data for a 3 × 3 image, each entry represents one byte. The three pixels of one line are
stored in 9 bytes, therefore each line is expanded to 12 bytes (next multiple of 4).
Offset Contents Remarks
20 R G B R G B R G B 0 0 0 Third (bottom) line of the bitmap
32 R G B R G B R G B 0 0 0 Second line of the bitmap
44 R G B R G B R G B 0 0 0 First (top) line of the bitmap
133