On Fri, 5 Apr 2013, Graeme Geldenhuys wrote:
Hi,
Having had a quick look at the FPReadBMP.pp unit, the only BMP format
FCL-Image supports is the Windows BMP format. I need to read OS/2 BMP
files too.
Here is a very brief comparison between the two formats. Note that OS/2
Bitmaps can be larger, multiple images per file, different compression
algorithms, different file headers etc.
OS/2 Bitmap:
http://www.fileformat.info/format/os2bmp/egff.htm
Windows Bitmap:
http://www.fileformat.info/format/bmp/egff.htm
I'm doing the work for fpGUI's DocView, but would like to share the code
with FPC too. What would be the suggested way of doing this?
1) extend the existing FPReadBMP.pp unit. This could be messy.
2) create a whole new unit specific to OS/2 Bitmaps.
I would opt for (2). But that raises another problem, but probably not
relevant to others here. If option (2) is used, your application can't
simply assume a *.bmp can be read with FPReadBMP, it needs to check the
file header first, then determine the correct unit & class to use to
read the bitmap.
That's why, unfortunately, I think 1) is better.
A second problem is the 'multiple images per file'.
You will need an image number when loading.
That will need a change in the reader or in TFPCustomImageHandler.
(a property, default set to 0, so it reads the first image (zero based))
Michael.
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