I like to go head and show you how to resize images. Now before we get too deep into it I am going to show you some problems with resizing and sizing down. So we have kind of little understanding what Photoshop does to our images when we resize them.
I opened a small 2×2 pixels image in the Photoshop. You can download this image here. I zoomed in the image too 800%. The image looks like this.
You can see that these are 4 pixels, 2 across and two down. Its black white then white black. What I am going to do is reduce the size of the image to 50% from 2×2 to 1×1 Pixels. So 50% is 1/2 of the size.
We have 4 pixel information, but what happens to the information when I reduce it to 1×1 pixels? The answer is, It goes away.
So lets see it. With the Image opened go to ‘Image > Image Size’ as Shown Below.
This will open a window shown below.
At the top we have pixel dimensions, that’s 2×2. And because ‘Constrain Proportions’ at the bottom is checked, we see width and height locked in the Pixel Dimensions area, Unchecking the ‘Constrain proportions’ will remove the locked icon infront of Width and height. But its good to keep it checked. with the ‘Constrain Proportions’ Checked type 1 in the Width Text field, it will automatically adjust the value of Height to 1.
Beneath that we have Document Size. This will not actually affect the size of our art work, But the Pixels per inch (Resolution) in the combination of inches would.
Now Hit OK at the Top right corner of window. You will see the image similar as below. (image zoomed to 1600%).
Now notice that we have lost out image details and we get is only grey color.
Now again go to ‘Image > Image Size’ and set the Width to 2 and Height will automatically become 2 if the ‘Constrain Proportions’ is checked. Click Ok.
You will see that our information is not regained. we again get the same grey color image. shown below. Information is based on what Photoshop sees.
Now Step backward 2 times by clicking ‘Edit > Step backward’ to get back where we were.
Now if you enlarge your image, then Photoshop will have to invent new information.
So go to ‘Image > Image Size’ And Type 50 in Width field, Height will automatically adjust itself to 50. Confirm that you have the following settings in the Image Size window.
Hit ‘ok’ and you will get the following image. (also zoom down to 100%).
We see that Photoshop have created new information. But in doing so it created a transition between white and black, it tends to get little blurry. It also happens to complicated images in which we have sharp edges, we would have slightly blurred images.
Now close this image I think I have pretty much proved the point with it.
Now open a new image with greater pixels. my is 800×600 Pixels. shown below.
Now we want to reduce its size to 50%. So go to ‘Image > Image Size’, Now Click on where it says Pixels next to Width, and choose Percent from the list. Shown Below.
Now in the Width Text field area type ‘50′. It will automatically adjust its height to 50%. Click OK. This will resize your image to 50 percent.
