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Litrus
Participant
February 28, 2015
Answered

How do i make the background for a BMP file, transparent?

  • February 28, 2015
  • 1 reply
  • 81612 views

I've been working on an icon for design reasons, and when i save the file as a .BMP, the background appears white. The file i work in has no background and it transparent, except for the icon of course. The dimensions of the icon are 32px by 32px. I can't upload the bitmap file onto this topic, apologies if that hinders anything,

This topic has been closed for replies.
Correct answer G_Hoffmann

BMPs cannot have transparency and that is that. It's inherent in the file format.

Mylenium


Windows Bitmap – Wikipedia

32 bit-per-pixel BMP (mode ARGB )has a leading byte, which is used by Photoshop

as alpha-channel for variable transparency. That's not a part of the BMP specifications.

It should be avoided, IMHO.

The reason for the introduction years ago has been the faster access by 32 bit

registers (opposed to 24 bpp).

Best regards --Gernot Hoffmann

1 reply

Trevor.Dennis
Community Expert
Community Expert
February 28, 2015

Unless there are compelling reasons to use BMP, make sure the background layer is turned off, and save as GIF or PNG

Litrus
LitrusAuthor
Participant
February 28, 2015

There is no background layer, and the file has to be in .BMP unfortunately, the place i'm uploading to won't take any other file source

G_HoffmannCorrect answer
Inspiring
February 28, 2015

BMPs cannot have transparency and that is that. It's inherent in the file format.

Mylenium


Windows Bitmap – Wikipedia

32 bit-per-pixel BMP (mode ARGB )has a leading byte, which is used by Photoshop

as alpha-channel for variable transparency. That's not a part of the BMP specifications.

It should be avoided, IMHO.

The reason for the introduction years ago has been the faster access by 32 bit

registers (opposed to 24 bpp).

Best regards --Gernot Hoffmann