cut down a bmp file ?

knowlesy · 13 Feb 2009 at 11:25

is there any software or how to to cut down all the extra data in a bmp file without having to compress it ?

note i cannot use png etc ...

El_Watcher · 13 Feb 2009 at 11:33

I may be wrong, but I thought the whole point of BMP is that it is an uncompressed, unoptimised format.
If you want to reduce the file size, you could try changing the colour depth.

Otherwise you will ahve to use a compressed format (png, jpg, gif).

uv · 13 Feb 2009 at 11:50

It's a bitmap image.. there is no 'extra data'.

The only way you can make a bitmap smaller is to convert it into a compressed/better format.

El_Watcher said:
use a compressed format (png, jpg, gif).

png is lossless.

mrk · 13 Feb 2009 at 12:16

You can't if it's being embedded into content, a bitmap is exactly that, uncompressed: p

If you're sending it to someone though or putting up for download then zip it or RAR it, you will bring the filesize down considerably.

knowlesy · 13 Feb 2009 at 12:17

there is loads of extra info malark in a bmp check out its wiki .... i cant use another file format due to the fact im using a program which cant accpet any other image type as it uses the bmp template as its background

its a 12 meg file but when rard is 606k

its constantly accessed of an already over used and abused network was just trying to improve it thats all ....

Burnsy2023 · 13 Feb 2009 at 12:26

knowlesy said:
there is loads of extra info malark in a bmp check out its wiki

Can you quote the bit that's relevant?

knowlesy · 13 Feb 2009 at 12:47

Burnsy2023 said:
Can you quote the bit that's relevant?

ooopsy

The bits representing the bitmap pixels are packed within rows. Depending on the color depth, a pixel in the picture will occupy at least n/8 bytes (n is the bit depth, since 1 byte equals 8 bits). The approximate size for a n-bit (2n colors) BMP file in bytes can be calculated, including the effect of starting each word on a 32-bit dword boundary, as:

in the v3 version of it states that it can be compressed

Note: OS/2 V1 bitmaps cannot be compressed and cannot be 16 or 32 bits/pixel. All values in the OS/2 V1 header are unsigned integers.

im just wondering how to compress it without usin g a zip rar etc