Can you post your IM version (convert -version) and platform and the result of identify -verbose test.pdf?
For my system:
Version: ImageMagick 6.8.9-5 Q16 x86_64 2014-06-30
http://www.imagemagick.org
Copyright: Copyright (C) 1999-2014 ImageMagick Studio LLC
Features: DPC Modules
Delegates: bzlib cairo fftw fontconfig freetype gslib jbig jng jp2 jpeg lcms lqr ltdl lzma openexr png ps rsvg tiff webp x xml zlib
I am getting the following from test.pdf.
Code: Select all
convert test.png -background white -alpha background test.pdf
Image: test.pdf
Format: PDF (Portable Document Format)
Mime type: application/pdf
Class: DirectClass
Geometry: 91x91+0+0
Resolution: 72x72
Print size: 1.26389x1.26389
Units: Undefined
Type: Bilevel
Base type: Bilevel
Endianess: Undefined
Colorspace: Gray
Depth: 16/1-bit
Channel depth:
gray: 1-bit
alpha: 1-bit
Channel statistics:
Gray:
min: 65535 (1)
max: 65535 (1)
mean: 65535 (1)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
Alpha:
min: 65535 (1)
max: 65535 (1)
mean: 65535 (1)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
Colors: 1
Histogram:
8281: (65535,65535,65535,65535) #FFFF
So perfectly opaque image.