I was hoping to hear some thoughts on this topic since, being a largely non-functional issue, I don’t think it has generated too much discussion.
Does anyone else have issues with palette constraints in Domino Designer? In the Help documentation, the restrictions on GIFs are described, but not much attention is payed to how the JPEGs get compressed. It looks to me like a custom 256 colour palette is generated (from the effect of the number of distinct colour gradients on gradient smoothness, for example).
I know that large images in a busy database are bad news for a Notes server, but the lack of control is frustrating - as if we can’t be left to make a prudent decision about it. Where’s the trust?!
Does anyone know of a best-fitting configuration for keeping images pretty? I know that decent progress can be made by tweaking the colours used in the image prior to import, but suppose our graphic features a large rainbow (it could happen) - what then? My vision is to be able to insert a low-compression JPEG image into the database directly, and avoid any optimising filters in Designer. I have no clue where to start though. All thoughts are welcome!
Subject: Curiosity: restricted palette for imported images
It’s not clear to me, if you’re talking about image resources, file resources, images imported into pages or forms from the file system, images imported into RichText fields in the client …
Subject: RE: Curiosity: restricted palette for imported images
Sorry, I didn’t specify since Notes and Domino Designer appear to handle each of those similarly. I’m not talking about file resources, however, but images imported for display. On the one hand there’s pasting an image in from the clipboard for display (either to a page, form, navigator or rich text field) and on the other there is, as you say image resource importing. In the former case, all approaches produce identical results, and in the latter compression is similarly applied, but either through compression artifacts or a low palette depending on whether you import a BMP/PNG/JPEG or GIF, respectively.
In no case is there any scope that I can see for compression adjustment. I just wondered if anyone had experience of getting optimal results with these constraints.
Subject: Curiosity: restricted palette for imported images
In my experience, if you add an image in the image resources and use it on the web, the quality doesn’t decrease, but if you insert the image resource on a form or page, the jpeg seems to degrade. I try to use jpeg’s with the highest quality (100) just to make sure.
Subject: RE: Curiosity: restricted palette for imported images
Thanks for your reply. I actually haven’t done much development for web browsers so I didn’t realise that was the case, but it’s useful to know. Interestingly, if you insert a low compression JPEG image resource into a page or form, it keeps its broad palette. Similarly, if you import the image directly from the file, it will keep its palette (albeit with more compression, as you note). But if you try to import the same source image directly into a navigator (you can’t load an image resource in this case), it seems to treat it as a GIF and imposes a custom 256 colour palette. Maybe this is just some necessary restriction on navigators. No difference is seen between Notes client and browser views, implying that the saved file contains the low quality image.
Subject: RE: Curiosity: restricted palette for imported images
I think you must be right about navigators. However, my boss likes them - and probably doesn’t want the mid-nineties -esque graphics that go with it. Maybe he does - but I don’t want to put my name to it!
Thanks for the suggestion about that option. I wasn’t aware of it, but didn’t have it checked myself - and wouldn’t expect many if any of my user base to have it checked, seeing as it isn’t by default. And even if it was, the Notes screens would look consistently limited; not only on my navigators.