So you just downloaded photos from your new fashionable Canon or Nikon camera? Well, get ready for huge high resolution photos! You are talking about 20+ megapixels and extremely high definition! Prices are always going down and quality is constantly increasing. For most people, this is overkill.
Plus, it can sometimes be tricky to manage all that extra quality in terms of size, storage, and sharing of photos with others. Of course, if you’re using a service like Google Photos, you can upload all of your photos at their own resolution and share albums that way, without having to zoom out.
However, there are times when you need to make an image smaller, for example, place it on a website or insert it into a Word document or PowerPoint presentation. Adding it at full resolution has no additional benefit and will only slow down your web page or make your Word or PowerPoint document huge.
Reduce the size of the image in Windows
For Windows, I like to use Paint. If you don’t need to resize hundreds of photos, Paint is great. Open Paint with a photo and you will see a Resize button on the ribbon.
Click on it and you can resize it in percentages or pixels. You can also automatically maintain aspect ratio or not.
If you want a more interesting program for resizing images, you can use a program called GIMP. It’s free and has some good image scaling tools. You can download it here:
Once you’ve installed it, open an image and click on Image and Image Scaling.
Note that in GIMP 2.8 you can merge all windows into one, not everything that floats all over the place. You can do this by going to Windows and clicking “Single Window Mode”.
If you find this way it is easier to work. Anyway, as soon as the image scaling dialog appears, you will see several options:
You can resize the image directly by adjusting the width and height. This is the most common way to scale an image. You can also adjust the resolution, which will allow you to view the image at its original size online, but will reduce the print quality. The spatial resolution that most screens can display is 72 or 100 (PPI or pixels / inch). This means that you can reduce the resolution to 72 or 100 pixels per inch without any noticeable difference in the image on the computer screen, and this will significantly reduce the size of your image.
Note that the most common resolution for computer screens a couple of years ago was 1024 × 768. Even if you go for a higher resolution like 1600 × 1200, you can still reduce the width of these really huge images to 1000px and they still take up the whole screen.
Also note that changing the width or height will keep the aspect ratio by default. If you click on the small chain on the right, it will “detach” and you can independently change the width or height, which will stretch the image. If you don’t want it to stretch, you need to crop the image, which is similar to scaling, but not the same since you are removing parts of the image. Scaling always saves the entire image.
Finally, you can choose an interpolation method that determines the quality of the scaling. It is set to Cubic by default. Here’s the difference between the different options:
No – pixel color is determined by the nearest neighbor in the image. This is the fastest method, but it can result in a blurry image.
Linear – The color of a pixel is determined by the average color of the four nearest pixels in the image. This makes the image smoother than the previous version.
Cubic – The color of a pixel is determined by the average color of the eight nearest pixels in the image. Pretty much the same, but again, the downscaled image is smoother and will give better results.
Sinc (Lanczos3) – This method uses the Sinc mathematical formula and performs high quality interpolation.
That’s it for scaling images in Windows.
Reduce the size of the image in OS X
If you want to scale an image in OS X, you don’t need to install any additional software. You can use the built-in preview program. When you open the image, click on “Tools” and then “Adjust Size”.
This will open a sizing dialog box, in which you have almost the same options as in GIMP:
You can adjust the width and height, and change the resolution if you like. It also tells you what the resulting size will be before you actually make changes, which is nice.
Zoom out the image in iOS
If you’re using your iPhone or iPad and want to quickly reduce an image to a specific size, you can try a free program called Image Size Most people seem to be up to the task.
It’s worth noting that the default Photos app in iOS can now do simple zooming, but only with preset options. Click on the photo and then click on “Edit” in the upper right corner. Several small icons will appear at the bottom of the screen. Go forward and click the rotate / crop icon at the far left.
Then you will see a new icon appear slightly higher in the upper right corner. This icon is for resizing the photo.
Now you can choose from a set of preset ratios. This includes square, 2: 3, 3: 5, 3: 4, etc.
For most people, this will be enough if they just want to post to Instagram and the like, so you don’t really need the app.
Zoom out the image in Android
Finally, let’s not forget about these Android users. Photo & Picture Resizer is a free application that allows you to adjust the size and quality of your images.
That’s all! Hopefully this applies to the most common operating systems and platforms that people will use to scale images. Have questions or comments? Post them here. Enjoy!