Resizing Illustrator Images (Photoshop to Illustrator)

I’m an experienced Photoshop user (though I only know the basics) who is just beginning to learn Illustrator (on a Mac). I’m working through some tutorials but am stumped on resizing images.

I imported a huge image from Photoshop - about 4,000 pixels wide - which I need to resize twice. First, I just want to reduce it to 1,000 pixels wide to trim my file size. I understand that I can simply grab a corner of the image with my mouse and manipulate it, but how do I keep everything proportionate? In other words, I don’t want to decrease the width by 200% and the height by 210%; I want the maintain the same ratio. In Photoshop, I just hold down a key - I think it’s Shift or Control - while manipulating the image, but that doesn’t seem to work in Illustrator.

I also discovered a Scale function, which I can apparently use to reduce the image by a percentage. But if I choose 25%, will that reduce the image only (leaving an enormous canvas with a huge file size), or will it reduce the whole thing? If the file size is 200 MB, I’d like to reduce it to, say, 25 MB.

After I make my initial size reduction, I’m going to add some colors, then reduce it again - probably to a width of about 200 pixels - before saving it as a gif or png.


I just tried an experiment, where I used the Scale function to reduce the image size by 75%. The file size was 1.3 MB both before and after I reduced the image size.

Then I created a new file, with a width of 1,000 pixels, rather than 4,000 pixels. I copied the reduced image from the original file and pasted it into the newer, smaller document. To my suprirse, it’s still 1.3 MB.

Hi -
Why are you bringing this gigantic image
into Illy in the first place?

I was working with a black-and-white line drawing in Photoshop - a map of Washington State featuring all the counties. I was afraid I might lose some details if I reduced it, so I decided to try and import the entire thing into Illustrator, trace it, then reduce it.

So far, so good…but I still haven’t figured out how to resize images in Illustrator. In Photoshop, I can click Image > Size, then type in in a width - like 250 pixels - and the height is adjusted accordingly. Does Illustrator have a similar feature that allows me to enlarge or reduce an image to a particular size?

Holding Shift keys works in Illustrator too - the proportions will be kept. Alternatively you can use “Transform” window (Shift+F8) and type in the values. Be sure to turn on the chain icon to link the two fields together (W/H).

Scaling will not change anything regarding the file size (weight). You are still using the same raster image, with the same amount of pixel data, so there’s no other way to reduce its weight than to resize the very raster image itself.

If you want to reduce the AI file size, then you can turn “Include Linked Files” option off when saving. Only the image location will be stored within the AI file, not the full raster image data.

Just import your huge raster image into Illustrator, trace it, and save as AI. As I like vector based objects, I would copy all the elements (ctrl+A, ctrl+C) into Photoshop (ctrl+V) and select “Shape layer” (or “Smart Object”), so they could be scaled without the quality loss.

OK, I get it - my file size is big because it’s linked to the original Photoshop document. I remember reading about linked files in one of the tutorials, but I haven’t really experimented with it yet.

I don’t understand your last statement:

As I like vector based objects, I would copy all the elements (ctrl+A, ctrl+C) into Photoshop (ctrl+V) and select “Shape layer” (or “Smart Object”), so they could be scaled without the quality loss.

I assume “all the elements” refers to every item in Illustrator, including the outline map and any other items I might have “placed” from Photoshop, right? If I click ctrl+A, ctrl+C, it will automatically copy EVERYTHING in my Illustrator file, after which I can create a new Photoshop file and paste it in. In Photoshop, I can then select “Shape layer” to modify all these items so they can be scaled.

So what you’re describing is a way to more or less vectorize objects in Photoshop, right? If the Shaper Layer function makes items scalable in Photoshop, then is there any reason I should learn Illustrator? I have read that text is crisper in Illustrator, though I haven’t experimented with that yet. But can the Shape Layer also be applied to text in Photoshop?

Photoshop is actually my preferred program, because I’m familar with it. I’m finding the Illustrator learning curve a little steep, but I thought it would be worth learning because of vectors alone. But if Photoshop’s Shape Layer function does the same thing, maybe I should just stick with Photoshop.


If you only design for web, Photoshop should be enough. There are some things easier to achieve in Illustrator, though.
If what you need as a final product is a raster image - you can stick to Photoshop and start learning its internal vector tools (shapes, pen tool).

Making a shape layer of the object copied into Photoshop, would be the last step after vectorizing the raster file in Illustrator:

  1. Prepare you raster image
  2. Import into Illustrator and trace (+ with linear artwork - outline strokes)
  3. Copy into Photoshop as a shape layer.
  4. Finish your design - scale, tweak, etc. your fully scalable vector-based shape layer.

Sharper than what? :shifty: It’s too vague statement. The text WILL be sharper when printed from a vector file than from a raster one. But if you want to create an image for a website and you do it in Illustrator, you are losing control over the pixels building your text, while with Photoshop you would have a range of tools to make the text sharper - sharpening filters, font control and anti-aliasing settings, etc.