help with png files

[Jspro]

hello new to Corel and am interested in whats called png? I am a Sketchup user (3d cad program) and would like to create portion of my model that I can see through. is there a youtube video that would show me how this is done or explain in elementary term how to do this? I included a gimp video so you can see what I'm trying to do . thanks john http://www.youtube.com/watch?v=Cw6rGpEOJv8

[LeviFiction]

The workflow is pretty similar.

Open up the image that you want to create a transparent PNG from, or start with a brand new image to make your own from scratch.

In the layers palette you'll see the default layer. This is usually what's known as a "Background Raster Layer." This is denoted by a white paper icon in the upper left corner of the layer on the layers palette. I'll be including a video to help demonstrate this. Background Raster Layers do not support transparency. So what we need to do is convert the Background layer into a regular Raster layer.

Right-click on the Background layer and select "Promote Background Layer" this will convert it into a regular raster layer. Similar to how adding an alpha channel to a layer in the GIMP works.

One it's a raster layer you can create a selection, or use the eraser, however you want to go about adding transparent areas to the layer.

Once you have your image setup the way you want it to appear in the texture go ahead and save it by selecting "Save As"

In the "Save As" dialog you'll see an "Options" button in the bottom right-hand corner of the dialog.

Click on that, then click "Run Optimizer"

In the Optimizer select the "Transparency" tab. Make sure to select use an "Alpha Channel" for the transparency. Also make sure it's using the layer's current transparency as the source for the alpha channel.

[Jspro]

thank you for your video I really appreciate that much easier for me to learn from watching you do this rather than reading text , kind of like doing brain surgery from a book. My question about the video is the magic Juan will it select from a photo or picture areas that you want to make transparent such as your video maybe the eyeballs or the mouth or the tongue in the area that's been closed in a line since the only tools I see that would work would be rectangular? All of the textures or pictures in SketchUp are usually jPEG files.I have also noticed while you were showing me in your video when you were showing me to choose the alpha channel you move your cursor over the smile face it had an eyedropper can you use the eyedropper to select eyeballs or mouth? Well thanks again I have a couple other questions about other how to do things in sketch up . I will post them on the bulletin board at some point I do appreciate again you helping me thanks John

[LeviFiction]

"Magic Wand" tool. It selects areas of an image that match a sample point. It can match based on Color, RGB values, Perceptual colors (Hue & Saturation), Brightness, and so on.

The "Contiguous" mode when turned on will only match pixels so long as there is a clear path between them and the sample point. If there is a clear line, or color change the matching won't get past these. When "Contiguous" mode is turned off PSP will match all pixels in the image that match the sample point.

Finally there is the "Threshold" value. "Threshold" will tell PSP to look for "similar" pixels. So you don't have to match exact colors, you can select colors that are close to each other. This is useful for photographs because shadows and light can make a color darker or brighter than the sample point so the threshold lets you account for variations like that.

I have some introduction to the selection tool tutorials that may or may not be useful to you:

Selection Tool: http://www.youtube.com/watch?v=riebYFgZ3mg

Freehand Selection: http://www.youtube.com/watch?v=ihWIX3Ifbe8

Magic Wand: http://www.youtube.com/watch?v=KeqB5IIv8A0

[Jspro]

i had performed the png in corel from the video and it turned the areas that should be clear into white ? not quite sure where i went wrong any ideas?

[LeviFiction]

How do you know it filled it in with white? Is it showing that way in Sketchup? Does it show it that way when you open it back up in PSP? Or are you looking at the image using Windows Preview?

If the image is actually being filled in with white (and it would show up that way in PSP so open it up again in PSP to be sure) then double check the settings.

The image must be 24-bit (8-bit color) image. It cannot be set lower than that. The transparency tab should be set to "Alpha Channel Transparency" and under "What areas of the image would you like to be transparent?" make sure you have selected "Existing image or layer transparency."

Also could you post the image?

If the image is showing up with white in Sketchup then I haven't a clue. Because I don't use sketchup.

[Jspro]

yes I wanted to let you know that I tried it again and this time it worked. This time I saved it a folder and then imported it into sketchup and low and behold there was clear transparent. Though I am using pictures taken from my camera some of the clouds we're still in the picture, when I hit the delete key they were still there and I tried to use the eraser tool but they weren't going away,something that I was doing wrong I suppose. I can only imagine pictures taken them from a camera our little bit more complicated but I really don't know I'm guessing. But thanks again I appreciate you making that video for me very thoughtful. John. PS if your interested in drawing in cad , sketchup is a free program to anyone that likes to model , it a very powerful program