[gs-devel] Ghostscript - Problem rendering image blank line

[Ken Sharp]

This mailing list is really intended for those developing Ghostscript, or 
developing applications using Ghostscript.

Currently we do not have our own forum for usage discussions, but the 
development team can be reached on the #ghostscript channel on IRC at 
freenode.net, we also monitor the ghostscript and postscript tags on stack 
overflow.


At 04:38 20/04/2011 -0700, isigui wrote:


>There is no errors really, only warning about fonts but in some of the jpg
>created, the images are not rendered correctly, they are plitted by a blank
>line.
>I posted an example below.

The image is not a single image, it is a number of horizontal images, 
stripes which have been scaled and positioned so that they butt precisely 
together. This kind of scaling only works reliably at a particular 
resolution and integer multiples of that resolution, it does not work 
reliably if the resolution is different.

You could try interpolating the images, providing they are not clipped this 
might give acceptable results. Use the -dDOINTERPOLATE flag. You could also 
try anti-aliasing (-dGraphicsAlphaBits=4).

Failing that you need to render to a higher resolution bitmap and scale 
down with interpolation using an image application (eg ImageMagick). At 
some point in the near future I expect a Ghostscript device capable of 
doing this and producing TIFF files to be completed.

         Ken