hello I'm Robin Whalleywelcome to Lenscraft today I'm looking at some of the
many ways you can use to resize your images in affinity photo when I first
started looking at this I had some real surprises so be sure to watch the entire
video there's also a full tutorial to accompany the video on my website I'll
include the link in the YouTube video description we'll start by looking at
something called the canvas every image you edit in affinity sits on something
called the canvas you don't normally see the canvas because it's the same size as
the image which then covers it it also doesn't show up in the layer
studio panel if you want to see the canvas you need to make it bigger than
the image when I click the document menu I can pick the resize canvas option then
I can enter the new size in pixels or I can use another unit of measurement by
changing the units drop down the anchor is also important because it sets the
location for the image once the canvas is resized if I pick the center anchor
the canvas will extend out from each edge of the image no you can see the
canvas which has a checkered pattern to show that is currently transparent if I
export this image as a PNG file the canvas will retain its transparency but
if I save it in a format that doesn't support transparency like JPEG the
transparent area turns white this produces a larger image but the actual
photo is still the same you can also turn off the transparency in the
document menu if you want to know you know what the canvas is let's look at
resizing the actual image possibly the most common way to do this is to use the
resize document option in the document menu
this opens the resize dialog where we can control different aspects of the
resizing at the top of the dialog I can enter a new width and height for the
image the closed padlock icon in the center locks the aspect ratio of the
image when we're resizing if I type in a new width and press Enter you'll see the
height field updates automatic in proportion this keeps the aspect
ratio of the image the same you can toggle the aspect ratio lock off and on
by clicking the padlock icon below this we have different measurement units
which you can pick from a drop-down list and below this you have the DPI and
resampling settings the DPI controls the number of pixels in each inch of the
image if I change the units to be inches you'll see that the 12000 pixel width
becomes 50 inches at 240 dpi affinity photo even includes a description in the
dialog to show this to you let's change the units back to pixels we'll watch
what happens to the number of pixels when I remove the resample option it
changes back to the original image size because resampling is how affinity adds
or removes pixels in an image if it counts our new pixels that pixel count
of the image has to stay the same let's change the units back to inches and
you'll notice I can now enter a new image size or watch what happens to the
DPI number if I set the width of the image to be 50 inches it reduces 226
because the affinity can't resample the image to create new pixels it has to
spread the existing pixels over the new image size in other words we have fewer
pixels per inch in the image I'll reset the resampling options and the DPI back
to 240 when the resampling options on I can pick one of the recent lling methods
these control how affinity creates or removes pixels in the image and
different methods have different strengths nearest neighbor is better for
things like diagrams and line art rather than photos bilinear is good for
reducing the size of images and bicubic for increasing them the tool and cross
methods give better results than the others but for photos they take a little
longer to process let's resize the image and look at the results the process is
surprisingly fast and when I magnified the image to a hundred percent the
results look very good
I'll go back to the original image now and I'll show you another way to resize
it this time I'll use the resize pixel art option in the document menu the
resizing options in this dialog are quite limited and I can only increase
the size of the image I'll use the two times option to double the size of the
image which should be just a little bit larger than the last example I can then
pick the method which is either hqx or XBR now I can't find much out about
these other than xbar is supposed to give a slightly smoother enlargement
I'll be using the hqx option for this enlargement the first surprise is just
how fast the resizing is it feels almost instant the other surprise is actually
the quality it's not quite as sharp as the lanczos method of resampling but
it's not far away and it's very usable having covered all of this we can now
look at a couple more options for image resizing the first is in the export
dialog when we can create a JPEG or TIFF file from the image in the dialog we can
change the size of the image that's created and pick the resampling method
to use the benefit of resizing when exporting is that you can keep the image
you're working on at its original size working on the original image size is
often easier when editing and these faster it also means you can produce a
master image and then use this to generate the other image sizes when you
need them now for the final method which you'll find in the export persona like
the previous approach you only create the resized image when you export it the
benefit of using the export persona is that you can batch up multiple exports
for the same image to do this we use the slicer studio panel it's call slices
because you can use it to slice up the image and export just small areas for
this example I'll use the default slice which is the entire image I can then
pick the file types that I want to create so I'll pick a TIFF file and a
JPEG for the TIFF file I'll output the image at is original
size but for the JPEG I'll create two enlargements of the image one at two
times and one at three times the original any size one of the limitations
of this method though is that you can only use the predefined size options but
you can pick the resampling method for each using the export option studio
panel once you've set up the options you can export the image individually or
export all of them at once now all the methods we've looked at have
their strengths and weaknesses but all of them can probably have a useful place
somewhere in your editing I hope you've picked up some tips for
the video if you have any others to share please add them in the comments
below I'm Robin Whalley you've been watching Lenscraft I'll see
you next week for another video