I have a number of images with aspect ratios varying from 10:8 down to 10:5. I want to send these for commercial printing on 12x10 paper with a 1" border on each edge to allow for mounting.
How do I produce a final picture at 12x10 with an appropriately sized border? I normally use DarkTable for image processing but I am up for any other piece of software provided the final image retains the embedded destination paper colour profile.
12x10 (inches?) with a 1" border = 10“x8”.
Assuming you want a pixel density of 300PPI, 10*300 x 8*300 = 3000 x 2400.
Your photos should not be larger than that.
In RawTherapee you would set the resizing tool to “bounding box” and set the bounding box width to 3000px and height to 2400px.
I don’t think I have explained myself too well. I need to supply a canvas that is 3600x3000 pixels in size with an image that is between 3000x2400 to 3000x1200 in size centred on the canvas.
In DarkTable I can specify a border that is a percentage of the image size but as far as I can see there is no way to do the above.
I can do it in the Gimp (version 2.10) by setting a canvas size and centring the image on this but it doesn’t look as though it retains the colour profile of the paper.
I don’t think I have explained myself too well. I need to supply a canvas that is 3600x3000 pixels in size with an image that is between 3000x2400 to 3000x1200 in size centred on the canvas.
Are the images already that size? Can be scaled in the command line, however keeping it simple.
A 3600x3000 @ 300 ppi white image 12x10.png, your photo.jpg @ 300 ppi, the icc profile from the printing company
convert -gravity center -composite 12x10.png photo.jpg -profile your-printing-co.icc out.jpg
Not everyone is comfortable with command line. This would be the ImageMagick command that you could easily add to a script (which I will leave out because I don’t know your OS):
convert input_image.jpg -gravity center -background white -extent 3600x3000 -profile printer_profile.icc output_image.jpg
If you are using ImageMagick 7, replace convert with magick.