Resize two face images to same size in PS?

wrote:

Hi All,
I hope there is an easy way to do what I am trying to do, and I appreciate the assistance. Scenario: I have two digital images of a persons face, and want to make a side-by-side new image with both (ie before/after photos.) The problem I have is both images need to be resized to the exact same subject dimensions (ie distance between pupils), and cropped.

Here is one way. It is not automatic, is easier if you have a good ruler and a calculator (and preferably a flatscreen monitor), but would not take long.

Suppose each picture is 2000 by 3000 pixels.

Open both pictures, set magnification to 100%.

Measure desired dimension on the screen for each picture (say in millimetres; the unit doesn’t matter).
Alternatively select the Info window, put the cursor on each point of interest, read the coordinates, and calculate the dimensions. (If the selected measurement is not horizontal or vertical you will have to use Pythagoras to get the slant distance.)

Calculate the ratio between the two measurements (assume this comes to 1.113 for example).

Divide one dimension of the larger picture by the ratio (2000/1.113 = 1797).

Resize the larger picture to this dimension, with ‘Resample image’ ticked.

The job is done. If you are keen you can take several sets of measurements, and average the resulting ratios.

James McNangle

wrote in message

Hi All,
I hope there is an easy way to do what I am trying to do, and I appreciate the assistance. Scenario: I have two digital images of a persons face, and want to make a side-by-side new image with both (ie before/after photos.) The problem I have is both images need to be resized to the exact same subject dimensions (ie distance between pupils), and cropped. There are subtle differences in the before and after subject size from holding the camera at a slightly different distance from the subject that needs to be corrected. (Ie. the head size is not the same in both photos). Is there an easy way to make the distance between similar features (eyes,ears,mouth,etc) on the subject the same in the before and after photos? Other software I seen allows you to mark the pupils (or other features) and resizes the images to the same proportions. I hope this is clear, and thanks for the help. John

Put the 2nd image on the first image as a layer. Drop the opacity down a little so that you can see both images, then move and resize the top layer to match the bottom. Once happy, return the opacity to full, copy the top layer to a new file and hey presto the two faces are the same size etc. I do this all the time as I am doing a montage of my own face through the years.

BC

Thanks James and BC.

BC…how are you resizing without doing all the calculations like James suggested? I’ve been doing James’ technique, but I have a lot of pictures,and I’m wearing out my calculator.
Thanks in advance.
JT

"John" wrote in message

Thanks James and BC.

BC…how are you resizing without doing all the calculations like James suggested? I’ve been doing James’ technique, but I have a lot of pictures,and I’m wearing out my calculator.
Thanks in advance.

Transform – Scale works.

"John" wrote:

Thanks James and BC.

BC…how are you resizing without doing all the calculations like James suggested? I’ve been doing James’ technique, but I have a lot of pictures,and I’m wearing out my calculator.
Thanks in advance.
JT

Try the following workflow
Create crosshairs from guides which are positioned at relevant points, eg. the pupils or chin and apex of the head in the first image. Move the second image, which you want to resize to the dimensions of the first one on top of the first image. Position it so that one of the two crosshairs is at the proper point. Now either the right or the left pupils on the two pictures shold be at the same position. Create a new window for this image (window->arrange->new window for filename.jpg). Make sure one window is at an enlargement which enables you to see the two crosshairs clearly and the other so that the whole of the top layer is displayed. In this last window load the transparency as a selection (Select->Load selection-> Layer 1 transparency). Hit Ctrl T to initiate free transform. Move the center point of the transformation rectangle to the position of the already aligned point (eg the left pupil). Now press the Shift and Alt (Win) keys, grab a corner of the transformation rectangle,and move it as required. This ensures that the point which is already aligned stays where it is. Move the corner until the other relevant point (the right pupil) of the top image has reached the second crosshair. This is best seen in the enlarged window. You can rotate the selection as well if required. Again, the image will rotate around the pre-aligned point.

HTH, Peter

"Big Craigie" wrote:

Put the 2nd image on the first image as a layer. Drop the opacity down a little so that you can see both images, then move and resize the top layer to match the bottom. Once happy, return the opacity to full, copy the top layer to a new file and hey presto the two faces are the same size etc. I do this all the time as I am doing a montage of my own face through the years.

A more elegant solution than mine. It has the great advantage that as well as scaling the image, you can rotate it to get exactly the same alignment in both pictures. Very neat!

James McNangle

"James McNangle" wrote in message

"Big Craigie" wrote:

Put the 2nd image on the first image as a layer. Drop the opacity down a little so that you can see both images, then move and resize the top layer to match the bottom. Once happy, return the opacity to full, copy the top layer to a new file and hey presto the two faces are the same size etc. I do
this all the time as I am doing a montage of my own face through the years.

A more elegant solution than mine. It has the great advantage that as well as
scaling the image, you can rotate it to get exactly the same alignment in both
pictures. Very neat!

James McNangle

I think this discussion was very interesting in the way some of us work in a very intutitve way with the tools and you found a very technical, mathematical precise solution.
I would have never dreamed of that math technique solution. I have had to replace people’s heads in group photos many times. I used the copy layer and paste over the pic I am trying to match it to, using transform to get the size, by eye.

"KatWoman" wrote in message

"James McNangle" wrote in message

"Big Craigie" wrote:

Put the 2nd image on the first image as a layer. Drop the opacity down a little so that you can see both images, then move and resize the top layer
to match the bottom. Once happy, return the opacity to full, copy the top layer to a new file and hey presto the two faces are the same size etc. I do
this all the time as I am doing a montage of my own face through the years.

A more elegant solution than mine. It has the great advantage that as well as
scaling the image, you can rotate it to get exactly the same alignment in both
pictures. Very neat!

James McNangle

I think this discussion was very interesting in the way some of us work in a very intutitve way with the tools and you found a very technical, mathematical precise solution.
I would have never dreamed of that math technique solution. I have had to replace people’s heads in group photos many times. I used the copy layer and paste over the pic I am trying to match it to, using transform to get the size, by eye.

That’s the good thing about Photoshop. It allows people to do different things to achieve the same results. So what is right for you may not work for others and so on.

Cheers
BC