Forum: Photoshop


Subject: AARGH! Please help with Transparency!

BAM opened this issue on Jun 20, 2001 ยท 14 posts


BAM posted Wed, 20 June 2001 at 10:32 AM

Attached Link: http://www2.gasou.edu/facstaff/bmunkasy/Transparency.htm

I am trying to create figures in P4 with Pro Pack and then display them on the web (Frontpage 2000 and IE 5.5). I would like the picture background to adapt to the background of the web page. I am using Adobe Photoshop 5.5 to change the file from .jpg to .png and to hopefully make the background transparent. After reading everything I can associated with Photoshop I do not understand what I am doing incorrectly. I have provided a link to a test page and an explanation of what I did in each picture. Any help you can supply would be greatly appreciated.

bonestructure posted Wed, 20 June 2001 at 6:05 PM

basically, you make the background a solid color that isn't duplicated in your figure. Then you set transparency by choosing the color of the background as the transparent color

Talent is God's gift to you. Using it is your gift to God.


soulhuntre posted Wed, 20 June 2001 at 8:04 PM

That only works with GIF;s of course. The option your looking for is in the GIF save box. Be prepared, it will be jagged as all hell. PNG can do it well - but it isnt supported enough to be a useful option.


bonestructure posted Wed, 20 June 2001 at 8:11 PM

The way to cheat is to make your web background a solid color, then make the background of your jpeg the same solid color. works as well as

Talent is God's gift to you. Using it is your gift to God.


soulhuntre posted Wed, 20 June 2001 at 11:40 PM

It's important to note that due to weirdness among browsers and OS's, you cant count on this 100%. The best thing to do is make a small jpg of the same solid color and use it as the background image for your pages.


BAM posted Thu, 21 June 2001 at 9:41 AM

Originally I tried to match the web page background to the picture background. In Photoshop once the RGB values are input you get the hex equivalent. I then set the background of the web page to that hex equivalent. However, when I overlayed they didn't match exactly. So I said well to heck with it I'll just let the web page background be the picture background by using transparency. Now obviously that isn't working either. Soulhuntre, Are you saying that I should make a small jpg of the background color and then overlay my picture over that jpg within the bowser?


soulhuntre posted Thu, 21 June 2001 at 1:01 PM

Yes. Due to browser weirdness, HEX colors are not always accurately rendered in HTML. JPEG's are always consistent. So, use photoshop to put your image on the back color, save it out as a non transparent image. Then save out a small (1x1 pixel works) JPG of the background color you used. Set that as the BACKGROUND image of the page in HTML. They page color and the image back will now match.


BAM posted Fri, 22 June 2001 at 10:29 AM

Thanks, I'll try it tonight.


Jim Burton posted Fri, 22 June 2001 at 8:16 PM

I find GIF transparency fully supported by every browser known to man (I don't think many are on text only ones these day). Seems to me if you create a image in PS 5.5 (Just paste the Poser image into a same size image with a transparent background, and use the alpha channel Poser includes to make an image mask) and transfer it to Image Ready, it will take care of all the details of converting it to 256 colors and doing a transparent background. Take about 60 seconds to do the whole deal.


soulhuntre posted Fri, 22 June 2001 at 8:20 PM

It will work .. but it will usually look like hell. The downgrade to 256 colors will be a problem to start - and then the edges will be very jagged on a poser figure. Imageready can't alias well without knowing the exact backgound color. Gif transparency channels are 1 bit, they don't have any alpha blend in them at all.


bonestructure posted Fri, 22 June 2001 at 8:26 PM

GIFs just aren't meant for photgraph level or complex colored graphics. They're designed to support graphics that are areas of solid primary colors. For anything else JPEGs are necessary. Me, I simply make my pages black and make the background of the image I want to use black. It's worked perfectly for me in every site and in every browser.

Talent is God's gift to you. Using it is your gift to God.


soulhuntre posted Sat, 23 June 2001 at 6:57 PM

Pure black and white will often work fine :)


mfarina posted Wed, 04 July 2001 at 12:18 PM

heh PNG transparency drove me nuts too till i found out that browser support for PNG stinks.


BAM posted Thu, 05 July 2001 at 10:48 AM

Silly me thinking that PNG transparency was supported. I guess the problem is that non-monopolistic Microsoft hasn't found the need to put them out of business by implementing their scheme.