<html><body bgcolor="#FFFFFF"><div>I think you did integer division. Something like "(double)width / (double)xImage->width" might solve your problem.</div><div><br>2011. 6. 28. 오전 12:05 Justin Anderson <<a href="mailto:justin@rayonix.com">justin@rayonix.com</a>> 작성:<br><br></div><div></div><blockquote type="cite"><div>I should mention that the source image is an 8 bit grayscale. Thanks.<br>
<br><br><div class="gmail_quote">On Mon, Jun 27, 2011 at 10:00 AM, Justin Anderson <span dir="ltr"><<a href="mailto:justin@rayonix.com"><a href="mailto:justin@rayonix.com">justin@rayonix.com</a></a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hello,<div><br></div><div>I'm trying to resize an X11 XImage which is a 640x480 pixel image from a video grabber, to be displayed on a window in an X11/Motif application.
</div><div><br></div><div>If I comment out the scale command in the following code, the image is displayed fine, albeit clipped on my window. If I uncomment the scale operation, there is no image in the window.</div><div>
<br></div><div>Any ideas? Thanks!</div><div><br></div><div><br></div><div><div><br></div><div> //Create a simple X11 window for displaying the XImage...</div><div> window = XCreateSimpleWindow(</div><div> display,</div>
<div> RootWindowOfScreen(screen),</div><div> 0, // x</div><div> 0, // y</div><div> width,</div><div> height,</div><div> 0, // border width</div><div> BlackPixelOfScreen(screen), // border</div>
<div> BlackPixelOfScreen(screen) // background</div><div> );</div><div> XMapRaised(display, window);</div><div> </div><div> //cairo stuff...</div><div> cairo_surface_t *surface_dest = cairo_xlib_surface_create(display, window, XDefaultVisualOfScreen(screen), width, height);</div>
<div> cairo_t *cr_dest = cairo_create(surface_dest);</div><div> </div><div> cairo_surface_t *surface_source = cairo_image_surface_create_for_data((unsigned char*)(xImage->data), CAIRO_FORMAT_RGB24, xImage->width, xImage->height, xImage->bytes_per_line);</div>
<div><span style="white-space:pre-wrap"> </span> </div><div> cairo_scale(cr_dest, width / xImage->width, height / xImage->height);</div><div><br></div><div> cairo_set_source_surface(cr_dest, surface_source, 0, 0);</div>
<div> cairo_paint(cr_dest);</div><div> cairo_surface_destroy(surface_source);</div><div><br></div><div> //Put the scaled XImage on the window...</div><div> XPutImage(display, window, gc, xImage, 0, 0, 0, 0, width, height);</div>
<div><span style="white-space:pre-wrap"> </span></div><div> cairo_surface_destroy(surface_dest);</div></div><div> cairo_surface_destroy(surface_source);</div>
</blockquote></div><br>
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