How to reduce the display on Mac

Shrink images: the best tips & tools for image compression

The different options for image compression

There are several ways to reduce the file size of images:

  • Reduce pixel dimensions
  • Reduce JPEG quality
  • Delete EXIF ​​data

Ideal for websites: make images smaller by reducing the pixel dimensions

Even smartphones now create high-resolution photos with 12 megapixels and more. The image quality is so high that you can print the photos as a large poster. You do not need the full resolution for display on the PC screen or smartphone. A reduction from, for example, 3,840 x 2,160 pixels to 1,920 x 1,080 pixels reduces the file size drastically. The differences are only visible when you zoom in on the reduced photos.

Decrease JPEG quality and reduce file size

Image editing programs such as the free GIMP offer the option of reducing the JPEG quality when exporting JPEG files. This reduces the file size of the JPEG images enormously, while the difference to the original is barely noticeable.

Delete EXIF ​​files and save additional storage space

Digital cameras and smartphones save information such as the coordinates of the location and the creation date of a photo in an EXIF ​​file. Deleting the EXIF ​​files saves storage space without affecting the image quality.

Reduce images with the on-board tools of Windows and Mac

Both operating systems offer on-board tools to reduce the size of images with little effort.

Scale images with Windows Paint

The Windows standard tools are sufficient; a single image is quickly reduced in size.

  1. Open the picture with Paint.
  2. Click on "Image> Resize" in the menu.
  3. Check the option "Keep aspect ratios".
  4. Either adjust the number of pixels or the percentage of the image size.
  5. Save the changes.

Shrink images with MacOS X

With a Mac, image reduction is also quick and easy:

  1. Preview the image.
  2. Click on "Tools> Size Correction" in the menu.
  3. Activate the option "Adjust size proportionally" and select percent as the unit.
  4. Change the height and width values, for example try 75 or 50 percent.
  5. The new file size is displayed in the window, and it is saved by clicking on "OK".

Batch processing tip: You can use the “Preview” program to reduce the size of several images in one go. To do this, mark the photos you want in the Finder and open them with the "Preview.app". Click the thumbnails in the left bar and perform the size correction. The files will be overwritten.

Scaling images and reducing image quality with GIMP for Windows, OS X and Linux

The free image editing program GIMP offers two quick ways to reduce the size of an image: Scaling an image and reducing the image quality when saving.

Scaling and reducing the size of images

  1. Open the picture and select "Picture> Scale picture" in the menu.
  2. The window shown in Figure 2 appears. If the chain symbol next to the input fields for width and height is closed, the aspect ratios are automatically retained.
  3. Select “%” as the unit and enter 75 percent, for example. Depending on requirements, a reduction to 75 or 50 percent can make sense.
  4. The conversion follows by clicking on “Scale”.

Reduce image quality and minimize file size

The second way to quickly reduce the size of an image is to reduce the image quality. To do this, click in the menu on "File> Export as", select JPEG as the output format and click on "Export". Another window is displayed; you can set the image quality using the slider. If the images are to be used on websites, a reduction in image quality to around 80 percent is useful.

Batch processing tip: The "David's Batch Processor" plug-in is available for quick processing of several photos in GIMP.

Batch processing: online tools reduce many images at the push of a button

Alternatively, there are handy online tools for reducing the size of the image. If necessary, try websites like CompressJPEG, Kraken.io, JPEG Optimizer, Optimizilla, and IloveIMG. The tools offer various setting options and sometimes reduce the size of the images by more than 50 percent. You can compress, scale, crop, batch process, and convert image files to other image formats, among other things.

Conclusion

You can use the programs presented to reduce the size of images quickly and easily. The smallest possible file size is particularly important for integration on a website. File sizes of less than 0.2 MB are usually recommended here. You can shrink individual images with Paint from Windows, the image preview from MacOS X or with free tools like GIMP. Tools such as IrfanView and the online tools are the ideal solution for reducing many images at once.

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