Recognize Loading BMP 16color/256color/24 bit etc.

[Agustin Tristan-Lopez]

I use the loadimagex control to load bitmaps, the bitmap is shown on the screen but the quality of the image is not the same if it is a 16 color, 256 color, 24 bit, etc. Nevertheless if I load all them using for instance MSPaint the quality is fine in all cases. What could be the reason I have a distorted image in some cases?
Regards.

[Semen Matusovski]

I guess, that there is no automatic SelectPalette hdc ...

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[Iain Johnstone]

You will find that BitmapInfoHeader contains most of the information about a bitmap (BitmapInfo includes this plus the colour table). You could therefore look at biBitCount to see the bits per pixel (values= 1,4,8,24) and arrange your program to suit this value. I recommend 'Graphics File Formats' by Kay & Levine, published by McGraw (ISBN 0-07-034025-0) to anybody working with graphics files.
You can protect your bitmaps from use outside your program by 'corrupting' the header - change the first two bytes of the file to anything, change the extension to another graphics format (I use IMG) and write to CD. No graphics software will be able to load your image. When you want to use it, copy the file the hard drive, change the first two bytes back to BM, then load this uncorrupted image into your program - don't forget to delete the uncorrupted file from the drive when have finished with it. You cannot protect against screen grabs!
Iain Johnstone

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[Agustin Tristan-Lopez]

Thank you guys! But I would insist a little bit.
In fact I can read the bitmapinfoheader and I now using GetDeviceCaps how is my video, nevertheless I cannot link both information in the control add imagex, it doesn't have configuration parameters.
regards
Agustin

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[Semen Matusovski]

agustin --
imagex simply executes loadimage. it's not enough.
a work with palletes not bad described in petzold's book (v ed.)
you can see one free translation from this book http://www.powerbasic.com/support/pb...ad.php?t=22632
format of bmp is described in many places.
it seems to me easy to register own control (similar http://www.powerbasic.com/support/pb...ad.php?t=17579
) and then follow petzold’s samples


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[Agustin Tristan-Lopez]

Thanks Semen. I shall try the code you've sent and modify according to my needs.
Regards
Agustin

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