Colour changes when converting from EPS to PNG

[SCHOLARGraeme]

Hi,

I am using the following command to convert an EPS image to a 24-bit PNG:

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convert Colours.eps PNG24:Colours.png

As you can see from the image below it doesn't replicate the colours exactly, with the original EPS appearing on the left and the ImageMagick conversion on the right:


The original EPS file can be downloaded here:
https://www.dropbox.com/s/p2r2zdow1lqb4fw/Colours.eps

Any idea if I am using ImageMagick wrong or if this is a bug?

I am using ImageMagick 6.8.8-9 Q16 x64 2014-03-16 on Windows 7

Thanks

[fmw42]

Your image is cmyk EPS (according to identify -verbose Colours.eps) and needs to be converted to sRGB. PNG does not support cmyk. It also results in missing colors that seem to be represented as transparency (see snibgo's comments below), so you may want to flatten against a white background. You may also want to set the density before reading the eps so that the output will be the desired resolution. I do not see much difference using profiles vs -colorspace.

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convert [-density XX] -colorspace sRGB Colours.eps PNG32:Colours1.png

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convert [-density XX] -colorspace sRGB Colours.eps -background white -flatten Colours2.png

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convert [-density XX] Colours.eps -profile /Users/fred/images/Profiles/USWebCoatedSWOP.icc -profile /Users/fred/images/Profiles/sRGB.icc -background white -flatten Colours3.png

Brackets on -density just mean that is optional

[snibgo]

The missing colours are probably the Photoshop spotcolors that can be seen in "identify -verbose colours.eps". These are colours that use special inks that may not be reproducible with RGB or CMYK.

[fmw42]

The missing colours are probably the Photoshop spotcolors that can be seen in "identify -verbose colours.eps". These are colours that use special inks that may not be reproducible with RGB or CMYK.

You are right. I missed that. The transparency may be coming from those missing spot colors. Odd that IM would use transparency for that. No actual transparency shows in the verbose info. That is, the file is CMYK and not CMYKA.

[SCHOLARGraeme]

Thank you fmw42 and snibgo and for the information about those spot colours.

The following command gets the conversion I am looking for:

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convert [-density XX] -colorspace sRGB Colours.eps PNG32:Colours1.png

Thank again.