hi, thanks for the inputs.. i could figure a way out based on the fact that scale greater than half gives a good resolution. so, right now i have done scale multiple times. e.g. to scale 0.25, scale 0.5 write to surface, take the surface, scale 0.5 and write again. this is giving good resolution. however this is slower. regards, Zaheer <div class="gmail_quote">On Nov 29, 2007 1:35 PM, Kalle Vahlman <<a href="mailto:kalle.vahlman@gmail.com"> kalle.vahlman@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">2007/11/29, zaheer ahmad <<a href="mailto:zaheer.mot@gmail.com"> zaheer.mot@gmail.com</a>>: <div class="Ih2E3d">> iam surprised by such basic issue. i hope iam missing something. i still > dont know why a scaled down image looks good in gthumb on desktop vs cairo > on a x86 scratchbox. Does it have to do something with graphic drivers > supported on desktop. </div>As Dan was pointing out, this is a known limitation/bug in cairo, and has been for quite some time:  "Cairo's software has a bi-linear filter. And when downscaling at a   factor greater than 2 the quality gets increasingly objectionable,   (and quite soon gets to something I would call horrible) . So unless   bi-linear means something very different than what cairo is doing,   it's definitely not sufficient for all downscaling."  <a href="http://lists.cairographics.org/archives/cairo/2006-June/007076.html" target="_blank">http://lists.cairographics.org/archives/cairo/2006-June/007076.html </a> AFAIK the situation has not improved since then, so unless willing to implement a better downscaling for cairo, your options are limited to using an external library to scale the image data or to "live with it". GThumb likely uses some more sophisticated (and undoubtedly somewhat slower) algorithm for it's downscaling, that's why it has far superioir results. I'm not sure if cairo supports scaling eg. xlib surfaces through XRender which could be in turn implemented with the graphics hardware to achieve both fast and good results. -- Kalle Vahlman, <a href="mailto:zuh@iki.fi">zuh@iki.fi</a> Powered by <a href="http://movial.fi" target="_blank">http://movial.fi</a> Interesting stuff at <a href="http://syslog.movial.fi" target="_blank">http://syslog.movial.fi</a> </blockquote></div>