Scanning to Scale

Importing the Correct Size Image into your Picture

Clive R. Haynes FRPS

Importing an image of incorrect size (particularly if it's too small) is undesirable, as significant upsizing by Edit > Transform > Scale (a form of resampling) will corrupt details.
It’s much better to import the image at the size you need.
This is how.
Although' actually' in this 'worked example'' the image we require to make the montage (composite) is a little larger than we need therefore some scaling-down will be necessary. However, the principle is precisely the same should the image to be added need to be 'scaled-up'
Below are the two images that we're going to combine. For this example, the cottage was scanned in at 1,350ppi
The cottage setting
The lady with a horse and cart to be added


1 Use the rectangular marquee tool to define the size of the area into which the new image is to be brought. This will establish the dimensions and therefore the 'size' of the image you wish to ‘paste’ into the space. See below

2 Look at the ‘Info tab’ (in the Navigator palette of options) and note the ‘W’ and ‘H’ sizes see 'Info tab' inset above, in this case W: 1.95 (cm)   H: 1.46 (cm)
3 Go to Image > Image Size and note the Resolution, expressed in Pixels Per Inch (ppi). In this case 1,350
4 Go to File > New and create a new document.
Its called ‘New’.
5 In the 'New' dialogue box, make certain that the Resolution is identical to the image you’re working on. If it isn’t then change it (simply type in the correct figure).
6 Enter the Width (W) and Height (H) as per the Info Box figures (W &H) from the image you’re working on.

7 Note the File Size - this will be used in a few moments Close the 'New' file – it only served as a reference to discover the file size required. See the 'screen grab' below - the W & H are as above (step 2) and the resolution as in step 3 - 1,350ppi and the all-important Image size is 2.31mb.

Now we have established the size of the file we need to import all we have to do is set the scanner so that the area of the image we wish to import indicates, in this case 2.31mb (or as near as we can get to it)



8 Go to your scanner and adjust the marquee around the area of the image you wish to import (try to keep the proportions similar to the area you intend it for).
9 To begin, set the scanner Resolution (ppi) to the same as the destination image (see step 3), in this case 1,350
10 Adjust the scanner to give the same or slightly larger file size (in mb) to that required – noted from step 7 as 2.31mb.
Do this by altering the percentage setting and/or the resolution setting (a series of guesses until about right) for the scan or by typing in the file size (Mb) required, however not all scanner software will give this latter option. If in doubt always opt for a slightly greater file size, as re-sizing downwards later, by 'Transforming' is not such a problem. All that you are aiming for is the correct file size in Mb. It doesn't matter how you arrive at this figure - whether by changing 'scale' or ppi (dpi in some scanners).
The 'screen grab' below shows how I adjusted my scanner to achieve - close enough!
11 Once you have the required figure, scan in the usual way.
After bringing the image into Photoshop, rotate the image so it’s the right way around If necessary.

12 With both 'windows' visible (that is destination/original image and imported image) use the ‘Move’ tool in Photoshop (arrow icon, top right of Tool Box) ‘drag and drop’ the newly scanned image into the picture area. Lo and behold, the image you have just imported is the correct size – or very close. And it appears on a separate layer.
See image below

Make any further small adjustments to size, if required, via the Edit ‘Transform’ menu.

To seamlessly fuse the two images together use the 'Layer Mask' technique - see the 'link' below
The final image with a few 'tweaks' - some shading applied
and shadows added to give a more authentic appearance

Related Topics
Layer Mask

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