Legacy ImageMagick Discussions Archive

I'm trying to convert images in various raster formats (JPEG, TIFF, GIF, etc.) into EPS, and I want to preserve the transparency, color space, etc. of the original image. I tried this with a TIFF with an alpha mask with IM 6.3.4, using the command:

convert big-masked.tif -matte eps3:big-masked.eps

but the resulting eps looks like seeing the image through Venetian blinds. It appears that the image data itself is ok, but the matte somehow doesn't match the line length of the rasters, so I get a repeating patter of horizontal bands of transparency interspersed with bands of image on a white background.

Anyone have similar experience, or know what the problem is? I can send both the original TIFF and resulting EPS if that would help.

Thanks,
-pd

I'm surprised there's been no reply to this. This is quite easy to reproduce.

From the appearance of the resulting EPS, I'm guessing that the alpha channel is not being padded to the right line length on output, so there's an underflow effect, where part of one row gets tacked to the previous row, etc. This, of course, causes the alpha channel to be misaligned with the image, resulting in this kind of Venetian blind look.

If I'm missing something what parameters to use to avoid this, please let me know. I've reproduced it with the 'convert' command and with the C interface.

Thank you,
-pd

Here's a sample of what the problem looks like. On the left is an EPS converted from an opaque TIFF on a gray background. On the right is an EPS made from a transparent TIFF on the same background. Both EPS files were created with ImageMagick's convert with eps3: as the output type.

Can you provide the above image, the source image and the exact commands used to re-create the problem on the Bugs forum. This looks like serious problem of unknown origin.

anthony wrote:Can you provide the above image, the source image and the exact commands used to re-create the problem on the Bugs forum. This looks like serious problem of unknown origin.

Sure. Is there a way to attach files to a post, or do I need to put them on an FTP server somewhere?

Thanks,
-pd