Mat and Frame Transformation

[Robert Schleif]

Suppose you have an image that is, say, 14" x 20" and you want to resize it with no cropping and print it with two borders simulating an inner and outer mat, that you want the narrower of the top or side borders of the outer mat to be 1.5" and you want to outside size of the outer mat to be 11" x 14" to fit a standard frame. I find that I would like to do something like this quite often, but that I cannot find a good way to do this without using the Resize Transformation first, doing some arithmetic on the side and then using my resized image with the Mat and Frame transformation. All the Mat and Frame transformation needs to make my operation trivially simple would be to add a "Bounding Rectangle" option to the Image options, and to add a "Final Outside Size" option to the Outer Mat options.

[jsachs]

First, you never have to resize the input image - just set Base Size On to Frame Opening Size. You still have to do some math to compute the mat sizes if you want to avoid cropping the input image. The problem with your proposal is that if you lock the frame opening size and the image proportions there are still many different ways to fit the image into the frame size - by changing any of the 4 outer mat widths, any of the 4 inner mat widths, or any of the 4 image borders.

The math is a little tedious but not difficult:

frame opening width = outer mat left + outer mat right + inner mat left + inner mat right + border left + border right + image width
frame opening height = outer mat top + outer mat bottom + inner mat top + inner mat bottom + border top + border bottom + image height

In your example, I assume you want no image borders, equal outer mat top and bottom, equal outer mat left and right, and equal inner mat widths, so this reduces to:

image width = frame opening width - 2*outer mat width - 2*inner mat width
image height = frame opening height - 2*outer mat height - 2*inner mat width

Given your example, and assuming a 0.5" inner mat width:

image width = 14 - 2*1.5 - 2*0.5 = 10"
image height = 11 - 2*1.5 - 2*0.5 = 7"

This is the image size you will get if you let PWP select the image size and, by coincidence, the proportions match the image proportions of 20:14 without any cropping and we are done.

But say you wanted to preserve image proportions of 20:16

So, if you make the outer mat width 1.5" you get an image width of 10" and if you make the outer mat height 1.5" you get an image height of 7" which produces proportions of 10 : 7. Thus you need to make the outer mat widths and heights different to preserve the image proportions of 20 : 16 (or 10 : 8). The way to do this is to keep the image height at 7" and make the image width (10/8)*7 = 8.75". This means you need to widen the outer mat widths to absorb the extra 1.25" (10.0 - 8.75 = 1.25) by adding 0.625" to each. In other words, make the outer mat widths 2.125" and the outer mat heights 1.5".

[Robert Schleif]

Thank you for your careful explanation.
How about a compromise? If "Base Size On" had the option of "Bounding Rectangle" and then reported the dimensions of the resized image, the rest would be easy.

[Dieter Mayr]

Just my thoughts:
I believe the problem fixed image size plus fixed frame size is quiet common.
One prints the image out at a cretain size and has a frame readily available.
I would find it very useful to be able to define frame and image size, and if one increases lets say the lower mat dimension a certain amount, the opper mat dimension decreases the same amount, to keep the image opening the same.
And the outer mat should change in the same way, too.
I think a possible restriction, if one uses just one mat, that may have to be the inner mat should be no problem at all.
;) I mean, hey, we have a computer, lets it do the calculation, and not have to bend our brain ;)

[jsachs]

I understand the problem, but the solution is really more complicated since you can adjust any combination of the image borders, inner mat or outer mat to make up the difference between the image size and the frame opening.

[Robert Schleif]

The solution is unique if one wants equal top and bottom borders and equal left and right borders, quite a common desire.
If one were provided with the dimensions of the resized image, then the arithmetic required for symmetric or asymmetric borders can even be done mentally.