Extra-large and medium-size photos


I am aware of memory and processing issues relates with huge photo files; disk space is not an issue, but processing load could be.

Most users will he happy with 1000 x 800 or 800 x 600, so it makes sense to limit the viewing size. But we occasionally use those photos for high-resolution printing @300 dpi in CMYK... and they are huge files (15-20 Mb).

Ideally, I would like to keep both versions linked in a certain way, as these 5-6 users are not in office and searching photos with Zen is simpler than in a generic file system.

So what would be the best solution ?

1. Load the extra-large photo and not worry about it? IOW, is it manageable on a good shared server? And is it a wise use of resources?

2. Reduce resolution manually. Then upload both versions in Zenphoto. Where / how would I load them so that Zenphoto considers them as 2 resolutions of the same photo?

3. Load only the medium-size photo in Zenphoto and store the hi-res in a (password-protected) folder outside the gallery? Could I have insert a description line like "download high-res photo at http:..." and make it so that only users with the need for high-resolution images would see the link?

P.S. Maybe some of that is in the documentation. If so, could anyone point me in the right direction?



  • If the server can process the large images at all, then you can just take the hit the first time the images are accessed. This is your option #1. Once cached, there will be no more processing done.

    If not, you will have to maintain a parallel structure for the big images and "manually" link to them. This would be your option #3. (You could place the parallel structure in the "uploaded" Zenphoto folder and get option #2. But I am not convinced that there is any advantage to this.)

    By manual linking, you would modify your theme and change where it uses the `getFullImageURL()` function. You would need to change that to some code which would create a link to your parallel structure image.
  • Thanks. I'll go for option 1. I was afraid that the cache would be automatically rebuilt at regular intervals.
  • acrylian Administrator, Developer
    The cache only rebuild if you clear the cache yourself. Zenphoto only generates cached images if an image in the size requested does not already exist.

    Regarding 300dpi images: You surely know that the dpi value does not matter on the net at all. The real pixel dimensions do.
  • Thanks for clarifying the cache-rebuilding issue.
    As far as 300 dpi... I know: it's the kind of thing I explain almost daily to the less technical folks at the office. I should have been clearer and talked about 3000x4500 px images; those typically take 4 Mb in RGB and 3 times that in CMYK.
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