• Registered: 2015-05-31
  • Posts: 7

Topic: Bad image quality

When using full screen mode on iPad 2 images look unsharp. When I open the same image on new window it looks great and sharp. I've tried images with original aspect ratio in different resolutions like 1200x*, 1600x* and 1920x* and the 1200 looks best out from those (obviously since iPad 2 has 1024×768 resolution). I also tried 16:9 aspect ratio with 1920x1080 resolution. Why doesn't the image look sharp full screen on Juicebox, but it looks sharp full screen when opened in new window? It fills the exact same are on both occasions anyways.

  • Registered: 2012-04-24
  • Posts: 5,924

Re: Bad image quality

Images in a Juicebox-Lite gallery are displayed using standard <img> tags (generated by the gallery's JavaScript code) and are scaled dynamically by the browser (as Juicebox-Lite uses the default value of imageScaleMode="SCALE_DOWN") so how the images look is somewhat dependent on the browser and its own scaling algorithms.
Out of interest, you might like to try using a different browser (Chrome vs Mobile Safari) to see if this makes a difference.
Perhaps the best solution would be to feed Juicebox-Lite larger images with a higher quality.
JuiceboxBuilder-Lite has default settings of 1024 x 768 at 80% quality. Try increasing these values to something like 4096 x 3072 at 90% quality (at least for testing purposes). Even if this produces images which are actually too large for a real-life gallery, if you get better results, it might hint that you would benefit from using larger resolution/higher quality images in your gallery than you currently do.
If you were using JuiceboxBuilder-Pro, I would recommend using a Multi-Size Image gallery.
Essentially, your gallery would contain up to 3 different sizes of images and Juicebox-Pro would use the most appropriate size, depending on the device being used to view the gallery. The Multi-Size Image logic also takes into account factors such as retina screens such as those on iPads.
Please see here for more details.

  • Registered: 2015-05-31
  • Posts: 7

Re: Bad image quality

I tried Chrome on iPad 2 and the result was the same. I unchecked "resize images" when I built all my galleries and made 5 different galleries which all had same images in different sizes: 1024x768, 1200x800, 1600x1067, 1920x1280, 2048x1365.

Also tried 2048x1152 which is iPad Air width with 16:9 ratio so the pixels are 1:1 on iPad Air and 2:1 on iPad 2. It looks ok on both tablets without any noticable quality differences between Juicebox vs new window, but then I tried 2000x1125 on iPad 2 and it looks blurry on Juicebox (as expected) but a lot sharper than 2048x1152 on new window. It looks worse on iPad Air than 2048x1152 though.

On 1080p PC screen there's no problems like this.

  • Registered: 2012-04-24
  • Posts: 5,924

Re: Bad image quality

The dimensions of the image will be determined by Juicebox depending on the size of the gallery and the imageScaleMode chosen but this really only affects the height and width dimensions of the <img> tags. Ultimately, the images are dynamically resized to fill the specified dimensions by the browser whose scaling algorithms cannot be changed.
All that can really be done is change the resolution and/or quality of the images in the gallery to see which settings provide the best results.