why slice images?

[Binky]

I never got this: If you have a large image it's advised to cut it up into smaller sections for faster downloads. But how is it faster to download, say, 10 5kb images than one 50kb image?

[Brian]

It will not make things faster to download, but will start showing parts of it faster.

-Brian

[Jeff]

If you have 5 10kb slices, they will actually take longer to download than 1 50kb slice.[nbsp][nbsp]However, one good reason to slice is if you can eliminate an area of white space.[nbsp][nbsp]If you are using GIF images, you can also use different numbers of colors (e.g. using just 4 for areas of text only, but more for areas which have graphics or images...)[nbsp][nbsp]Be careful though, especially with jpeg compression, that the edges don't show with different levels of compression or color reduction.

[Mandi]

It's also vital for using javascript mouseover effects on particular parts of an image, but not others . . .[nbsp]

[Mandi]

PS, check through the forums for discussion on a slick little app called Dicer, if you want to do this regularly[nbsp][nbsp]. . .

[Paul]

Hi there Mandi..

The dicer you are referring to, can be found here:
http://www.aota.net/Software_For_Download/imagedicer.php3

Thanks,
Paul

[Nicole]

Anyone with experience of Ulead SmartSaverPro 3 as an image slicer?

Thanks.
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Nicole Grada

[Shalazar]

I have to disagree.[nbsp][nbsp]Slicing and optimizing slices does indeed facilitate quicker downloads.[nbsp][nbsp]The comparison of 5 10kb slices to 1 50kb image is flawed, IMO, because the whole point of slicing is to avoid that.[nbsp][nbsp]You can selectively apply palette reductions, or even complete format changes to various slices, and optimize each based on its contents.[nbsp][nbsp]The end result is a graphic whose components are smaller in total weight than the original, and who are optimized for their various contents for the best display and download.

[Jeff]

Exactly my point :)

[Dan Kaplan]

I haven't tried SmartSaver Pro 3, but I think v2 is a great optimization utility.

The major thing to keep in mind when deciding whether slicing up an image is preferable is the makeup of the image itself.[nbsp][nbsp]Individual segments will *always* be larger than the sum of the whole.[nbsp][nbsp]In some cases this can be countered by selective optimization of sections, but not always.[nbsp][nbsp]A large image that is fairly evenly colored throughout will be better off left intact, unless you want sections to load independently for the illusion of quicker loading.

Dpress
[nbsp]- How big is your stuff sack?

[Justin]

But isn't the whole greater than the sum of it's parts? ;)[nbsp][nbsp]

In reality - you're talking about more separate connections, which means more HTTP headers (both ways, mind you), more GIF/JPEG headers specifying each file's color palette, and so on... so unless you get a significant reduction in total file size, I'm against dicing the image. For faster load appearance, use an interlaced GIF where applicable.

By the way - the thing about different color palettes only applies to GIF images. A JPG is still 24 bit color, with a different compression all together, and I don't think you would gain anything by dicing a JPG at all (or should I say you would not lose anything? Whatever - you get my drift I'm sure :))

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Justin Nelson
FutureQuest (http://www.FutureQuest.net/index.php) Support
[This message has been edited by Justin (edited 07-24-00@04:08 am)]

[Dan Kaplan]

I don't think you would gain anything by dicing a JPG at all Probably true from a file size standpoint, but not necessarily in terms of making the most of the file type.[nbsp][nbsp]Jpeg's are lousy for sharp edges like text, so selectively optimizing certain areas could prove beneficial.[nbsp][nbsp]Smooth color sections, on the other hand, can often be reduced ~75% in size.[nbsp][nbsp]I will often split logos into jpeg and gif sections because a large chunk of gif text generally smaller and clearer than the same file as a jpeg.

Dice