While not necessary to use, you have the option to utilize a locally installed version of Photoshop to optimize images for the device you are designing for. Using Photoshop to downscale images typically results in a higher quality of the images displayed on a mobile device. Downscaling is different than image resizing as this option literally changes the number of pixels in an image, potentially resulting in a change in the quality of the image.
- For more information on settings for resampling an image, read the Adobe Photoshop Help article "Image size and resolution."
Enabling Photoshop downscaling
1. Go to InDesign and show the mag+ Settings Panel.
2. Place a checkmark next to "Downscale Images Using Photoshop".
3. Configure the settings by which you would like to resample images.
- Nearest Neighbor: This is a fast but less precise method that replicates pixels. This method is best used with illustrations containing edges that are not anti-aliased, to preserve hard edges and produce a smaller file. However, this method can produce jagged effects. Best used for Verticals that only contain illustrations.
- Bilinear: A method that adds pixels by averaging the color values of surrounding pixels. It produces medium-quality results.
- Bicubic (Default): A slower but more precise method based on an examination of the values of surrounding pixels. Bicubic produces smoother tonal gradations than Nearest Neighbor or Bilinear.
- Bicubic Sharper: A good method for reducing images with enhanced sharpening. This method maintains the detail in a resampled image. If Bicubic Sharper oversharpens some areas of an image, try using Bicubic. Best used for Verticals whose images are going to end up at a lower resolution for older devices without a high-density display.
- Bicubic Smoother: A good method for enlarging images and designed to produce smoother results. Best used for Verticals whose images need to be upscaled to a higher quality for newer, high-density displays.
This is the version of Photoshop installed locally on your machine.
4. Export your Vertical.
Photoshop will now be invoked during the export process to go through the images in your Vertical and resample them accordingly.