asked on

StretchBlt Distortion On MY Screen

I use StretchBlt to display bitmaps thst I earlyer created with Photoshop V. 4.0.If the bitmap file was prepared rom a previouse scaned photo than the output is fine.If it was a cartoon taken from a Clipart cd-rom, than it is looked mostly grayscaled and only few areas looked ok, in the c program (while in Photoshop it looks fine).
I tryed to save the bitmap file in different modes(Indexed,RGB...)but nothing helped.

Thanks In Advance

Lesher Izack

NickRepin

Call SetStretchBltMode before stretching the bitmap.

Try different parameters for iStretchMode of SetStretchBltMode.

nietod

Are you making the image larger or smaller?

lesher

ASKER

Even if I try to open the bitmaps with Bitblt(and not in Strechblt) it does not help.It means the problem exists somewhere else.

Thanks

nietod

>> if I try to open the bitmaps with Bitblt(and not in Strechblt)
You can't "open" them with these functions.

>> it means the problem
>> exists somewhere else
Why?

If you stratch a bitmap it will look different. You can't avoid that. If you increase the size the bitmap will begin to get "chunky" That is, you will start seeing large blocks of pixels and the edges of things will become "jagged". If you scrink the bitmap you will loose detail. Small peices of detail will be lost, faint portions may dissappear, the image may become darker (all this depends on the mode), but in any case the results will be a degradation in the image qauality.

ASKER CERTIFIED SOLUTION

xLs

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

nietod

>> StrechBlt may with some graphic cards be hw
>> accelerated, which means it could give quite
>> good quality
It can't prevent degradation of the image. Nothing can.

nietod

lesher, do you understand how experts exchange works?