[Gimp-user] Gimp channel mixer

[programmer_ceds <forums gimpusers com>]

I've just tried converting a file from jpg to tiff with ViewNX V2.10.3.

When opening in GIMP I get an error message about a null byte in the date field
but it then opens the file as two layers with the top (active) layer being the
thumbnail exactly as you said. Looks like this is a bug in ViewNX2.

Exporting a file in GIMP with the thumbnail selected doesn't cause this problem.

At least you have a workaround.

> Good morning all,  The image I was working on was created by Nikon's
> ViewNX2 editor, the original image format was Nikon's raw image .NEF
> extension, I exported this as a TIFF and then imported it to GIMP.
>
> In ViewNX2 the images are stored with a preview thumbnail, so I think
> you have hit the nail on the head, I got myself confused at first
> because I didn't notice the thumbnail in the image  before  I used the
> channel mixer. The image is an infrared photo, it's mostly sky and the
> thumbnail didn't stand enough for me to notice it. It's also so tiny
> that it can't be seen in the image layer page 1. After swapping The
> red and blue channels (not green, another mistake) the colours changed
> enough for the thumbnail to be obvious. I wrongly assumed that the
> channel mixer had created the thumbnail, in fact it was there all the
> time.
>
> Now I understand the problem I think I'll be OK, for a while anyway.
>
> I bought Klaus Goelker's book "GIMP 2.8 for photographers" last week,
> I'm working my way through it and thought I was doing OK, but I got
> myself too confused to sort this one.
>
> Before installing GIMP I read a review which said that GIMP was a very
> good program, but the learning curve was steep. I  think they were
> right on both points.
>
> Thankyou for your assistance, I know what I'm going to be doing during
> the long winter nights.

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