[Xerte] Re: FW: jpgs degrading - is this a new phenomenon?

[Pat Lockley]

I think you notice it on these pictures as JPEGs don't handle lines very
well.

Usually the internet rule is when using text, use a GIF as gifs don't
pixelate lines like a jpg does.

When given big blocks of colour, like on a photo, jpgs are fine

On Sat, Jan 14, 2012 at 8:37 PM, Ron Mitchell <ronm at mitchellmedia.co.uk>wrote:

> Hi Alistair****
>
> This is all quite predictable and not a server or flash player issue -
> just a simple fact of viewing raster images at different to actual size.
> Your LO is set to full screen try switching to default so it's 800 x 600
> and you'll see that some pages look better at that size and others look
> better at full screen? ****
>
> ** **
>
> It wouldn't help with all your images but for the example here what about
> using the Charts > Table page type e.g.
> http://itq.jisctechdis.ac.uk/xerte/play_85****
>
> HTH****
>
> Ron****
>
> ** **
>
> *From:* xerte-bounces at lists.nottingham.ac.uk [mailto:
> xerte-bounces at lists.nottingham.ac.uk] *On Behalf Of *Alistair McNaught
> *Sent:* 14 January 2012 17:45
> *To:* Xerte discussion list
> *Subject:* [Xerte] Re: FW: jpgs degrading - is this a new phenomenon?****
>
> ** **
>
> A final version with 3 pairs of images (jpg v png) at  sizes 300, 360 and
> 550 respectively. In all cases jpgs show significant degradation. PNGs only
> show degradation at the 550 px point where they are being shrunk from 550
> to 470 to fit the space.****
>
>  ****
>
> In the short term I’ll stop using jpegs in favour of pngs and gifs but in
> the long term I’d be really interested to know why jpegs fare so badly.
> They will be the format of choice for a lot of less technically inclined
> users so if it ispossible to determine whether the code has changed and if
> so to change it back I’d be very grateful. ****
>
>  ****
>
> That’s all the excitement needed for one weekend – I’m signing out now!***
> *
>
>  ****
>
> All the best and thanks for the rapid responses Dave and Pat.****
>
>  ****
>
> A****
>
>  ****
>
> *From:* xerte-bounces at lists.nottingham.ac.uk [
> mailto:xerte-bounces at lists.nottingham.ac.uk<xerte-bounces at lists.nottingham.ac.uk>]
> *On Behalf Of *Pat Lockley
> *Sent:* 14 January 2012 17:08
> *To:* Xerte discussion list
> *Subject:* [Xerte] Re: FW: jpgs degrading - is this a new phenomenon?****
>
>  ****
>
> It looks like XOT is stretching them, and so is having to fill in bits
> (which is degradation via interpolation, which sounds redundant but lacking
> the words to find a better one - negative amelioration?)****
>
>  ****
>
> The originals are fine.****
>
>  ****
>
> What's the maximum size? 640 something?****
>
> On Sat, Jan 14, 2012 at 5:02 PM, Alistair McNaught <
> Alistair.McNaught at heacademy.ac.uk> wrote:****
>
> Hmmm – here’s the test I did for Pat:****
>
> First 2 slides of http://itq.jisctechdis.ac.uk/xerte/play_82 show
> significant quality difference yet the image below shows they are virtually
> identical in their raw form.****
>
>  ****
>
> ****
>
>  ****
>
> Curiouser and curiouser..****
>
>  ****
>
>  ****
>
>  ****
>
>  ****
>
> *From:* xerte-bounces at lists.nottingham.ac.uk [mailto:
> xerte-bounces at lists.nottingham.ac.uk] *On Behalf Of *Dave Burnett
> *Sent:* 14 January 2012 16:56
> *To:* Xerte list****
>
>
> *Subject:* [Xerte] Re: FW: jpgs degrading - is this a new phenomenon?****
>
>  ****
>
>
> >does it look equally blurry on your PC on that slide? ****
>
>  ****
>
> Yes.****
>
>  ****
>
> Vista/Chrome****
>
>  ****
>
>  ****
> ------------------------------
>
> From: Alistair.McNaught at HEAcademy.ac.uk
> To: xerte at lists.nottingham.ac.uk
> Date: Sat, 14 Jan 2012 16:48:14 +0000
> Subject: [Xerte] Re: FW: jpgs degrading - is this a new phenomenon?****
>
> Hi Dave / Pat – thanks for quick responses****
>
> Yes these shots are all on same laptop – it appears to be a new problem. *
> ***
>
> The only PCs I have access to are all the same spec but I’d be interested
> if it looks different on other people’s PCs – for example the LO I first
> spotted it on yesterday is at ****
>
> http://itq.jisctechdis.ac.uk/xerte/play_79 and page 14 is a slide show
> navigator. Slide 4 on page 14 is shown below as it renders for me and the
> original image is also shown superimposed. Notice how the table has become
> blurry. It wasn’t always like that .. does it look equally blurry on your
> PC on that slide?****
>
>  ****
>
> ****
>
>  ****
>
>  ****
>
> Alistair****
>
>  ****
>
>  ****
>
> *From:* xerte-bounces at lists.nottingham.ac.uk [mailto:
> xerte-bounces at lists.nottingham.ac.uk] *On Behalf Of *Dave Burnett
> *Sent:* 14 January 2012 16:36
> *To:* Xerte list
> *Subject:* [Xerte] FW: jpgs degrading - is this a new phenomenon?****
>
>  ****
>
> Sorry, those are both on the same screen aren't they.****
>
>  ****
>
> How about Flash version then?****
>
> I'm just wondering if they way Flash handles the rendering.****
>
> Same effect on a different machine?  ****
>
>  ****
>
>  ****
>
> From: d_b_burnett at hotmail.com****
>
> To: xerte at lists.nottingham.ac.uk****
>
> Subject: RE: [Xerte] jpgs degrading - is this a new phenomenon?
> Date: Sat, 14 Jan 2012 11:28:37 -0500****
>
> Latest video drivers?****
>
>  ****
>
>  ****
> ------------------------------
>
> From: Alistair.McNaught at HEAcademy.ac.uk
> To: xerte at lists.nottingham.ac.uk
> Date: Sat, 14 Jan 2012 16:26:22 +0000
> Subject: [Xerte] jpgs degrading - is this a new phenomenon?****
>
> This seems weird but yesterday I was demonstrating a learning object to
> some colleagues I was working with and I noticed that the images which I’d
> carefully crafted to be crisp and sharp and fit the available space were
> looking pixellated and ugly with lots of jpegy artefacts (like when you
> save a jpeg at too coarse a setting and get fuzz around lines etc). The
> originals I uploaded are much higher quality. ****
>
>  ****
>
> ****
>
>  ****
>
>  ****
>
> However no such degradation is apparent with PNG files as shown below: (as
> before the original is at the bottom and the Xerte rendered version at the
> top). In this case the quality is indistinguishable.****
>
> ****
>
>  ****
>
>  ****
>
> Is something taking place in the upload that degrades the jpgs or how is
> this oddity explained. For the short term I can use PNGs rather than JPGs
> but it introduces an extra work layer and It doesn’t help the dozens of LOs
> that used to look crisp and now look fuzzy. Any suggestions gratefully
> received!****
>
>  ****
>
> A****
>
>  ****
>
>  ****
>
>  ****
>
>  ****
>
>  ****
>
> Alistair McNaught****
>
> Senior Advisor ****
>
> *JISC** TechDis*****
>
> C/O The Higher Education Academy Building****
>
> Innovation Way****
>
> York Science Park****
>
> YORK****
>
> YO10 5BR****
>
>  ****
>
> 07870567659****
>
> Skype: alistair_techdis****
>
> http://www.jisctechdis.ac.uk<http://www.jisctechdis.ac.uk/?utm_source=emailsig&utm_medium=email&utm_campaign=sitelaunchmail>
> ****
>
> *http://www.scoop.it/t/inclusive-teaching-and-learning *****
>
>  ****
>
> Interested in pragmatic inclusion- focused staff development?
> See JISC TechDis ITQ for accessible IT practice<http://www.jisctechdis.ac.uk/techdis/pages/detail/floating_pages/ITQ_Accessible_IT_Practice>information and taster
> resource <http://itq.jisctechdis.ac.uk/mod/resource/view.php?id=5>. ****
>
>  ****
>
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