Skin colour

[Erik Heyninck]

Thanks for the support.

BUT before I continue, I want to make it clear that I do really appreciate Michael's remark. I like it when people put the finger on a weak spot in my reasoning or work because I can learn from them. And Michael is right, absolutely right.

Perhaps I chose my words a little too black and white. Lets say I need(ed) a short retreat to delve into the matter and to get a deeper knowledge. Enthusiasm is necessary, but as kerosene simply burns up in the air when there is no engine to explode in (and make that work), so enthusiasm needs form. And form means limitation, structure. Michael added structure and showed how my engine was leaking. (if you can follow my example).

So you won't get rid of me that easy, but before posting out of sheer enthusiasm, I'll take a look at as much sides as I can, and if someone finds a weak spot, I'll be grateful. Teachers have to be severe AND encouraging.

So friendship to everyone. Let's make this forum like Xara's!

And now a question:

When you save in PS6 as JPEG, do you have the possibility to choose for 4:4:4, or are you limited to 4:2:2?
To me this is rather important because 4:2:2 is quite ok for photographs, but not for real shart transitions like complex fills and fractals. In these cases, 4:4:4 is visibly much better.

PS5LE doesn't offer this posibility. [img]/infopop/emoticons/icon_cool.gif[/img]

[Beth]

Erik, I am not really sure what you mean by 4,4,4. I sort of remember another ap doing this...maybe it was Xara. (?)

But in any respect, you have TREMENDOUS control over how images are saved to gif or jpegs. Both of these file types are controlled by sliders. The jpeg slider for instance offers you the complete range from high quality/low compression to low quality/high compression. And you can view the effects before you save the file.

But best of all is the control you get when using image ready (that comes with PS6). You can control the colour tables easily and have colours snap to their web safe equivalents with very little effort. Then you can slice up images and image ready will write the code necessary to keep everything alligned in a table for you.

Here is one thing I just did in imageready/photoshop:
http://www.artifax-design.com/client/contents.html

I could select the various slices (which translate into HTML cells in a table) and compress them according to the content. This comprised of gifs with varying degrees of compression. Lots of cells have a transparent giff in them. To do this in IR, you select the slice and select 'no image'. This really helps to reduce total file size. Other slices are giffs with only 2 colours, while others have 4, 8 and a couple have 32 colours. You can go higher too if you want, but in this case there was little loss of quality by reducing the colours in the gif. And any of the colours in the colour table can be set to snap to web safe colours. You can even save a colour table and use that for what ever slices you want.

The tables are not just limited to gifs. You can have a combination with jpegs as well and you can also individually control how each slice will compress.

And all this while getting an on screen representation of the optimized file. Similar to Xara's setup, you can view 2up or 4up compression schemes to compare file size and image quality.

I really like this. Mouseovers and animations are also done in IR. Really really cool.

Oh, that page I put up is something I am working on now so it is not finished. I just posted it to get some help in the GoLive forum as I am not sure how to best handle the slicing and dicing in IR for best control over the HTML. and BTW, the total byte count on that page is 23 K with only 17 for all the images. I think that is pretty good for such a graphic page.

Convince you yet [img]/infopop/emoticons/icon_wink.gif[/img]
Beth

[Erik Heyninck]

Hi Beth,

I have Boxtop Pro JPEG, and it gives the smallest Jpegs I've ever known, and at a very good quality. But up to now, Photopaint is the only one I've found that gives the 4/4/4 option.

Jpeg was made for real life photographic images. Most information on a photograph is not that important, so Jpeg takes the average value of squares of 8x8 pixels. (this is an oversimplification. if you're interested, I can describe the exact way in which it works.)
And you can decide which information level is to be considered relevant or not, hence the compression.
But there is also a second chapter to Jpeg.
As I said, it was conceived for real life photographs. But imagine a drawing you made. You used bitmap fills, fractals etc... Now you have sharp edged transitions as well.
And the "normal" jpeg has problems with sharp transitions. Normal is 4:2:2. What does this mean?

Jpeg does not use an RGB colour model, but one of it's own. Because the people who designed it accepted that the human eye is more sensitive to changes in brightness that changes is hue, they put up a brightness channel, and two colour channels. this causes a second type of loss, called "subsampling". 4:2:2 means that for every 4 pixels of brightness data, there are only two pixels of colour date per channel. To get visibly better images-with sharp-transitions, you need as much data for brightness as for colour: 4:4:4.

When you anti-alias a little and can give 4:4:4 to your drawings with complicated fills, fractals etc, you get a visibly better quality.

And I only wondered if PS6, being THE state of the art bitmap software, offered this possibility. It seems not. Pity.

On slicing: I have Dreamweaver/Fireworks, and they do a good job together. Fireworks even lets you decide which data in an image you consider important ( example: the focus of interest, like the eyes of a portrait) and keep these sharper than the rest of the (blurry) background.

But thanks for the info on PS6. I'm shure it is worth upgrading. But for now, I spent enough, and it has to wait.

Still one thing: I know professional people, AND with Mac AND with PC who complain that when you open a series of photographs in PS6, one after the other (not together) that it doesn't "empty" the RAM and freezes. . And they do have enough RAM, and give PS enough memory. They went back to PS5.5 for this reason and this has no problems with the same files. Sounds familiar to anyone?

[Erik Heyninck]

I Know this "should" be a gif, but it is a good example of the difference in subsampling mode.

Try to arrange it that you see both on your monitor (full screen if necessary). The difference is...see for yourselves.

Made in Photopaint9. Saved as jpeg, 20(80) quality and saved as standard 4:2:2

[Erik Heyninck]

4:4:4. See the difference at the edge of the two objects.

[s.winders]

There is quite a differnece isnt there,and I assume that would make 2.4.4 images better for sharpening etc.


As far as I know the PS 6 issue with temp files not being chucked was sorted out with the 6.1 update Erik.Also with PS 6 you can optimize different areas of images like you mentioned above,you can use an alpha channel in save for web for this purpose and I assume its the same in Image ready as well.


Stu.

[s.winders]

I mean 4.4.4.

Stu.

[Beth]

Hi guys

I did jpeg of your example for comparision. I saved as a jpeg with 80 quality. I could go higher to 100% quality, but might as well keep the tests similar.

So what does the 4,4,4 stand for. or does it mean SNAFU

[Erik Heyninck]

I don't know what SNAFU means (I'm Flemish).

The Jpeg you made is MUCH better than the 4:2:2 "normal" quality. Good. The file is some 12% bigger than the 4:4:4, but the quality is at least of the same quality.

4:4:4 means that there is as much data of each colour channel as there is of brightness. Sorry if my explanation is unclear. Technical English isn't easy for me, and I have to write it online, without time to construct my argument.

I like this. I'll make a tiff, and test that out in all the JPEG exporting software I can, with the same quality setting.

If you don't work against time, time often works for you.

[mikeius]

Sorry if in some way I offended you. It is not my intention.

I don't tell people that they are or aren't wrong. I just ask, because asking I learn as well. It push all of us to think, and thinking we improve our knowladge, at the same time we learn from each other.

There is a big problem with digital art. What is the value of it if we can't print what we create, or if it print differently. In today world, prepress has become artist responsability, so we should learn prepress techniques.

Again. If in someway I offended you, I sincerelly appologize.

Best regards