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Manual GIF dithering for blurred objects/transparent images

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Your Text: Insert Slimies » Insert UBB Code » Close Last Tag \| All Tags UBB Help	Another mini-tutorial from mahjqa: [quote] I do use scanlines, yes. It's clearly to see in my last post in this thread: [URL=http://www.ozoneasylum.com/Forum14/HTML/001363.html]Call 911[/URL] I've whipped up a bit of a mini-tut of what I did. Get the PSD at [URL=http://www.mahjqa.com/stuff/transparencylamp.psd]http://www.mahjqa.com/stuff/transparencylamp.psd[/URL] if you want to do it yourself. Much more fun this way. [IMG]http://www.mahjqa.com/stuff/scanl1.gif[/IMG] This is what I started off with. The layers are, from bottom to top: Background. Simple, color: #2B0404, which is the average of the background colors of this forum. Lamp. Just a painting of a lamp, doesn't do anything in this example. Light. It's the big spotlight thing you see. I made this one with [filter>render>lighting effects.] Hue/Saturation is used to give the lamp a blue color. Both Light and Hue/Saturation are in the layer map called 'light map'. The blending mode of this map is set to 'screen', which means that whatever is IN this map, will be treated as [i]one flattened layer[/i] which is set to the blending mode 'screen'. I could export this one. I usually export things this way: I select the complete canvas, I click [edit>copy merged], and paste that in a new, empty document. Then I use the eyedropper tool to get the color of the background. Then I click [select>color range] (I set the fuzziness to 0) to select just the background color. Pressing delete removes the background, and now I can export it as a GIF. However, if a GIF has to be blended against different backgrounds, that doesn't always work. That's why I use scanlines at times, especially when I work with gradients or large blurred areas. [IMG]http://www.mahjqa.com/stuff/scanl2.gif[/IMG] Here, I added a scanline layer. For info on how to make one, [URL=http://faq.ozoneasylum.com/897]visit this :FAQ:[/URL]. I set it to multiply, so every other line of pixels disappears. Since that is a little bit too much, we're going to limit it a bit. Click on the arrow in the layers palette, and then on 'blending options'. [IMG]http://www.mahjqa.com/stuff/scanl3.gif[/IMG] There's a bunch of options here, but you need to look for two sliders which look like this: [IMG]http://www.mahjqa.com/stuff/scanl4.gif[/IMG] If you move the lowest white triangle slider to the left like on the screenshot, you'll see that the scanline effect disappears slowly, starting at the brightest spot. What these slider things do, is that they limit the area where a layer is visible. The top bar compares the brightness of the layer itself to the amount of the sliders, the bottom one compares the brightness of the layers that are below the layer itself. The concept may be a bit hard to grasp at first, but after a bit of fiddling it'll become clearer. You notice that the transition where the scanlines stop is a bit harsh. To smooth this a bit, you can hold the ALT key (I believe mac users use the OPTION key for that) and click and drag the white arrow, like in this screenshot: [IMG]http://www.mahjqa.com/stuff/scanl5.gif[/IMG] The white arrow splits in two, so the transition is less harsh, creating a nice scanline effect. Since you only need the scanlines in the darkest parts of the picture, you can move the sliders even more to the left. The end result looks something like this, a lamp that blends nicely against both backgrounds. [IMG]http://www.mahjqa.com/stuff/scanl6.gif[/IMG] [/quote] and a further addition: [quote]Yeah, both work. Maybe a checkerboard is even better, but I just thought the scanlines looked nifty :) (and a bit easier to see in the tutorial) EDIT: Also, another way I use this, is to add color to images. Most of the time when I draw something, I do so in black and white. (first picture below) To add color, I use adjustment layers like hue/ saturation. Most of the time, 1 color doesn't really work well. (second picture.) To tweak it a little, I often add more layers. In the third picture, I added a red hue/saturation layer. Using the blending options, the layer is 100% visible at the darkest places, and 0% visible in the lightest, so the yellow shows through. And the fun part of this is, I can draw below those adjustment layers, just using balck, white and greys, without having to worry about the colors. [IMG]http://www.mahjqa.com/stuff/colorisation.gif[/IMG] [/quote] [url=http://www.ozoneasylum.com/Forum14/HTML/001368.html]from[/url] ----------------------------- Relevant threads: [url=http://www.ozoneasylum.com/Forum14/HTML/001368.html]sig things[/url] ----------------------------- Relevant FAQs: [internallink=5208]How do I make my animated gif's background transparent?[/internallink] ______________________ [internallink=4626]Emperor[/internallink] [small][i](Added by: [url=http://www.ozoneasylum.com/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Emperor]Emperor [/url] on Fri 22-Aug-2003)[/i][/small] [small][i](Edited by: [url=http://www.ozoneasylum.com/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Emperor]Emperor [/url] on Fri 22-Aug-2003)[/i][/small] Loading...
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