need help

[ssg2003]

Hi all,

I need help with how to optimize this image so that certain regions of the image appear clean. I followed the tut on slicing but I still can't get a clean image, at least when it comes to text over a jpeg image. I need to know if there is a better way to work with this image? I always have problems like this whenever I use the gradient feature. See attached.

Thanks in advanced for your assistance.

Best regards,
Steve

[ssg2003]

Hi all,

I need help with how to optimize this image so that certain regions of the image appear clean. I followed the tut on slicing but I still can't get a clean image, at least when it comes to text over a jpeg image. I need to know if there is a better way to work with this image? I always have problems like this whenever I use the gradient feature. See attached.

Thanks in advanced for your assistance.

Best regards,
Steve

[Simon Beck]

Not sure what you mean. With that image I wouldn't use JPG at all - I'd use a GIF with error diffusion to avoid the horrible compression artifacts you get with jpeg on plain blocks of colour. With that kind of gradient you'd hardly notice the dithering from a GIF

[This message was edited by Simon Beck on March 16, 2004 at 13:16.]

[gwpriester]

I agree with Simon.

Sometimes if your image is too large, then you may have to use JPEG, but for text over an image a GIF or 8-Bit PNG file, with diffusion if necessary (your file size will be smaller if you do not use diffusion) will product a better result.

JPEG images are especially bad if you have large areas of solid colors and especially especially bad if the color is red.

Gary

Gary Priester

Moderator Person


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www.gwpriester.com </a>


<a href="http://www.xaraxone.com">
The Xara Xone </a>

[Albacore]

Go with Gary's advice and if you have a copy of Fireworks somewhere on your hard drive use it as it normally does a much better job for producing quality, small file size graphics for the web.

[ssg2003]

I use Ulead and Xara X to optimize my images. Using Fireworks at this point would take more time than I have to complete my project. I do have question though. What is error difussion and how is it referred to in Ulead and Xara?

Thanks for the advice and tips.
Steve

[Egg Bramhill]

Steve
The help file on this issue gives the following:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> You can select between three types of dithering with these options. Choosing None means there will be no dithering, Ordered using an ordered (regular) dithering pattern and Error diffusion uses error-diffused dithering (a more complex dithering technique). In general, error diffusion will give the best results, but only use dithering when really necessary as it prevents the file compression working so well and so makes files larger. You cannot use Ordered dithering with an optimized palette.

Note that you can set the dithering type for the screen display too, see Changing the screen dithering.


©1995-2001 Xara Ltd. <HR></BLOCKQUOTE>

The best way is just to experiment with these options and view the output on as many computers as you can.

Take a look here
Or even better here
I don't know how much validity this now has as 8 bit colour is fast becoming a thing of the past. I notice that on one of my sites only 5% of visitors now use 8 bit monitors.
Egg

[This message was edited by Egg Bramhill on March 20, 2004 at 22:01.]

[OklaEd]

Hi Steve ... I can answer part of your question.

"Digital halftoning, or dithering, is the technique commonly used to render a color or grayscale image on a printer, a computer monitor or other bi-level displays. A particular halftoning technique that has been used extensively in the past is the so-called error diffusion technique."

The Floyd-Steinberg algorythm has been considered the industry standard for years ... but there are numerous new algorythms being tested and used to attempt to push the envelope on printing speed and monitor resolution.

Charles or Gary should be able to tell you whether or not XaraX has a form of error diffusion in it's bitmap effects. I can't help with Ulead because I don't use it.

-Ed.

[ssg2003]

Thanks to everyone for the feedback and tips. Xara has an error diffusion option, but Ulead is still questionable.

Thanks again,
Steve