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Posted on 24/09/04 00:44:56 AM |
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Martin Kimeldorf
* Posts: 20 Reply  |
Uploading images
This may seem like a simple question, but I'm curious what strategy people use when they upload a file and have to resize it to fit a 200K limit. Assuming you might be starting with a 300ppi image, what steps do you take? |
Posted on 24/09/04 08:03:32 AM |
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trinityofone
Guest Reply |
Re: Uploading images
I use Save for Web and a balance of resize and quality. If it's just something rough, I'll use really low quality 20-40%. _________________ It must be Thursday, I never could get the hang of Thursdays |
Posted on 24/09/04 08:08:29 AM |
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Steve Caplin
Administrator Posts: 7021 Reply  |
Re: Uploading images
The first step is to reduce the resolution to 72dpi, which is best for viewing on screen. For viewing in the forum, the best size to aim for is around 600 pixels wide. Change both using the Image Size dialog. Then, as Trinity says, Save for Web is the best way of reducing file sizes so you can see the end result. |
Posted on 25/09/04 04:22:37 AM |
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Martin Kimeldorf
* Posts: 20 Reply |
Re: Uploading images
I tried a combination of both of yours that looks like this sequence: 1) Reduce res to 72ppi, with largest side set to 600 pixels, then Save as Jpeg quality#8 2) To further reduce...Save for Web...quality set to 90. This got me right on the money size wise and not bad quality. Do you guys think this is just a fluke of this file? Does this look too labored? Might it apply to other picts? |
Posted on 25/09/04 09:23:24 AM |
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maiden
Golden Gif Gagster Posts: 471 Reply  |
Re: Uploading images
All pictures can be made suitable for web by using the Save for Web function of Photoshop, and Trinity is spot on with using quality setting between 20-40%. 90% as you mentioned is pushing it a bit. One trick is to create a quick loading low-res image as a link to a more high-res version, which gives the viewer the opportunity to chose. The html code for this is <a href="url to your high-res image" target="_blank" \><img src="url to your low-res image" \><br>click image to view high-res image</a> Remember that with the internet there is a very steep trade-off between image quality versus speed of loading you should be aiming in general for images of around 40-60k with larger hi-res images you should use the method as described above. Take a look at my thumbnail gallery each thumbnail is less than 5k, usually 2-3k. This allows for quick page updating but each thumbnail is a link to it's higher quality file. http://www.maidenart.co.uk/gallery.php _________________ mad as a badger and twice as furry |
Posted on 25/09/04 10:08:09 AM |
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trinityofone
Guest Reply |
Re: Uploading images
What you have to bear in mind, is JPEG is like any other type of compression. The technicalities loosely defined are; it looks at your image and groups blocks of colour. It then converts it to a kind of code, in which it writes something like '20 pixels of value X, 5 pixels of value Y', and so on. So, if you have an image that has a large amount of one colour, it will be smaller than one which is very busy, even when you use the same settings. The two images below are exactly the same size and both saved using save for web at 20% quality. The wasp is 24k but the butterfly is only 11k 
_________________ It must be Thursday, I never could get the hang of Thursdays |
Posted on 26/09/04 07:40:52 AM |
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Martin Kimeldorf
* Posts: 20 Reply |
Re: Uploading images
Two last questions... Would there be any advantage to first saving as a jpeg at say 72ppi, quality 8...and then re-saving using Save For Web menu at the quality settings you suggest (say 20-40%)? And, do you tend to worry about the pixel dimensions. For example, it was suggested earlier that 600 pixels might be the widest for this forum. Would that apply elsewhere as a general rule as well? |
Posted on 26/09/04 07:41:21 AM |
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Martin Kimeldorf
* Posts: 20 Reply |
Re: Uploading images
Two last questions... Would there be any advantage to first saving as a jpeg at say 72ppi, quality 8...and then re-saving using Save For Web menu at the quality settings you suggest (say 20-40%)? And, do you tend to worry about the pixel dimensions. For example, it was suggested earlier that 600 pixels might be the widest for this forum. Would that apply elsewhere as a general rule as well? |
Posted on 26/09/04 09:51:31 AM |
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maiden
Golden Gif Gagster Posts: 471 Reply |
Re: Uploading images
No advantage whatsoever, jpeg compression creates artefacts around areas of high contrast, by saving in jpeg quality '8' it will have already inserted some artefacts - further jpeg compression upon this image will only result in a further exaggeration of the artefacts. You are much better off taking the original high quality image and reducing to 20-40% straight away than taking this two-step process. Alternatively consider using .png which is a lossless format but the file sizes are larger and then apply a jpeg compression to the .png image. This is experimental as I've never tried it before but it might be worth playing about with. Becky _________________ mad as a badger and twice as furry |
Posted on 26/09/04 7:27:56 PM |
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Martin Kimeldorf
* Posts: 20 Reply |
Re: Uploading images
Thanks for all the feedback...using your advice and a few experiments i determined that my basic approach to uploading for the web will be the following...and trials have proved it out: 1) In the size box reduce image to 72 ppi and largest dimension to 600 pixels. 2) Then go to Save for Web and choose a quality of about 40% Thanks...if it is not in the book, i hope something like this shows up there. |
Posted on 26/09/04 7:41:55 PM |
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maiden
Golden Gif Gagster Posts: 471 Reply |
Re: Uploading images
Actually Martin, Save to Web automatically makes it 72ppi so really there is no need to do so beforehand. If however you are reducing the overall Image Size then choose 'Bicubic Sharper' from the Resample Image menu in the Image Size dialogue box this will produce a much crisper image on resizing. But Save to Web also has the same options to resample and resize the image suitable for web. Becky _________________ mad as a badger and twice as furry |
Posted on 26/09/04 8:50:49 PM |
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Steve Caplin
Administrator Posts: 7021 Reply |
Re: Uploading images
Maiden/Trinity, Really great explanations from both of you! Thanks for going into this much detail, it really helps. Becky, how the hell do you know all this stuff???? |
Posted on 26/09/04 9:35:25 PM |
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trinityofone
Guest Reply |
Re: Uploading images
I had heard that SFW reduces to 72dpi, in fact, it was one of the reasons I was given for why, when you use SFW, it will ask to save changes on the original image. One thing that must be remembered, is to set your colour profile (if you have one) in the SFW dialogue, otherwise, the end result may look significantly different to the original. _________________ It must be Thursday, I never could get the hang of Thursdays |
Posted on 26/09/04 10:53:03 PM |
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maiden
Golden Gif Gagster Posts: 471 Reply |
Re: Uploading images
Primarily I started out designing my webpages having only an Amiga linked to the internet through a 56k modem that worked far slower with the weak processor of the Amiga - Optimisation to the fullest extent was my cross to bear for that period. Then I got my first PC, but things didn't exactly speed up that significantly but at least I had Photoshop to be creative in and Save to Web was the greatest thing since slice bread to me as before I had to optimise using other usually rubbish programs that tore the heck out of the quality. Thank you Adobe for saving my sanity 
_________________ mad as a badger and twice as furry |
Posted on 26/09/04 11:37:46 PM |
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trinityofone
Guest Reply |
Re: Uploading images
Aha, a fellow ex-Amiga user! Those were the days; Deluxe Paint, etc. I remember when people were in awe of 'IBrowse', the first browser to render transparent GIFs. The miggy was still the only true multi-tasking home computer though. Macs used the same technology, although they used more powerful Motorola CPUs. Talking of Macs, I decided to see how much a fairly low range G5 would set me back; for a dual 1.7ghz, with 1gb RAM, 160gb HDD, Nvidia 5200/64mb and a 20" cinema display - c£2,900. I think I need to arrange that heist.... _________________ It must be Thursday, I never could get the hang of Thursdays |
Posted on 27/09/04 10:51:32 AM |
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maiden
Golden Gif Gagster Posts: 471 Reply |
Re: Uploading images
Then you have to buy all your software afresh, Trinity. Which is why I'm sticking to my PC for the time being anyway. They say the Mac is better, but is it much better or just a little better? I've often wonder whether it was more of a status thing to own a Mac rather than a great leap in technology, but then I don't own one and and have no real experience of using one either. Can you, Steve, shed some light on whether the Mac is a quantum leap beyond the PCs? Becky _________________ mad as a badger and twice as furry |
Posted on 27/09/04 11:14:45 AM |
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trinityofone
Guest Reply |
Re: Uploading images
The Mac's CPUs are considerably faster than their PC equivalents. They're 64bit RISC, a 1.7ghz MAc CPU is around the equivalent of a 3ghz P4. You also have to consider that the Mac uses pretty much uniform hardware, so the OS and software will run far more reliably than Windows, as Windows has to configure itself to whatever random hardware you have installed. Me, a convert? Possibly but as I say, way out of my league at present. _________________ It must be Thursday, I never could get the hang of Thursdays |
Posted on 27/09/04 4:03:40 PM |
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russ davey
Guest Reply |
Re: Uploading images
We could have a seperate thread for this old debate, as old as the hills, and best illustrated by Steves image with a really nasty looking beige 386 PC juxtaposed with a pretty imac. I think despite mac users saying PCs are not as stable, since XP that argument doesnt hold so much weight, of course Windows 9x machines were terrible for crashing every few hours, but XP is very similar (some would say a rip off!) of Mac OS X. PCs may have compatibility problems occasionally, but that isnt so much a problem these days, granted it was a problem back when 386s were about and Pentium 1s! At the end of the day for me, it comes down to image, and Macs are beautiful, PCs arent, if youre a designer, you need to be seen to be on the mac side, because PCs just arent cool amongst designers. I prefer PC, because you can build them, change parts and do it cheaply, hyperthreading allows a P4 to act as two seperate CPUs (much like a mac with two processors) so multi tasking is better. But I would be tempted to chuck in all that interchanging and ease of use, possibly for a beautiful mac. Having said that, whats up with only having 1 mouse button - would drive me nuts!!  |
Posted on 27/09/04 4:24:20 PM |
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trinityofone
Guest Reply |
Re: Uploading images
Hey! I have a really pretty PC! It's black acrylic, not nasty beige  _________________ It must be Thursday, I never could get the hang of Thursdays |
Posted on 27/09/04 4:43:48 PM |
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Steve Caplin
Administrator Posts: 7021 Reply |
Re: Uploading images
I've had this argument so many times I can do it in my sleep now... it's like a religious war, there really is no right and wrong. One thing I've noticed, though, is that when friends of mine have creative jobs they have Macs (and this includes friends who are or have been TV producers, carpenters, graphic designers, potters, magazine editors, whatever). But when they move into more businesslike roles - when the TV producer became a media manager, when the editor became a publisher - they moved from Macs to PCs. I'm still not sure why that happens. I think it all boils down to the fact that people who care about how things look prefer Macs. It's not just the box, it's the whole operating system: the fact that I have a row of icons at the bottom of my screen that zoom up to 128 pixels square when I slide my mouse over them. They look gorgeous, and although it doesn't add a jot to my productivity it makes me feel good every time I see them. But, really, it's just personal taste! |
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