Forum: Photoshop


Subject: Newbie compositing/masking question

jasonmit opened this issue on Aug 02, 2003 · 13 posts


jasonmit posted Sat, 02 August 2003 at 3:16 PM

I have two images I would like to composite because I found that my image looks better with one section not antialiased. I have 3 images. The first completely antialiased, the second with no antialiasing, and the third a mask of the section (sofa pillows) I'd like to not have antialiasing in the final image. In easy, step-by-step language, how can I composite these images so only the pillows are not antialiased? Note: These images were created in another app.

retrocity posted Sat, 02 August 2003 at 10:16 PM

Put image one (anti-aliased) on the lower layer.
Put the image two (non-anti-aliased) on a layer above image one.
Use the quick mask icon and paint the pillow areas.

i'll do a quick screen cap...

BRB
:)
retrocity


retrocity posted Sat, 02 August 2003 at 10:44 PM

here's a quick shot:
  1. add your image
  2. add your next image
  3. click the quick mask icon
  4. fill the mask with BLACK and paint away with WHITE the area you want exposed (or what you want to be seen...)

REMEMBER:
Black=masked
White=transparent

Using the Quick Mask mode lets you edit your selected area on the layer as a mask without using the Channels palette and while viewing your image. The advantage of doing it this way is that you can use almost any Photoshop tool or filter to modify the mask.

You could also add a new channel and add the mask you created into it. it's just the quick mask is faster...

:)
retrocity


jasonmit posted Sat, 02 August 2003 at 10:50 PM

If I was to do it using my already created mask, how would I do that? I ask because due to disability, I can only use the keyboard to move the mouse pointer limiting me to 8 directions. Thus, freehand painting is out. The mask was easily created in Bryce without painting.


retrocity posted Sat, 02 August 2003 at 11:05 PM

Sure thing jason, just do the first and second steps (creating "layer one" and "layer two") but this time with image two selected, click on the **Channel** tab and create a new channel (this will basically be an *alpha channel*) you can paste your mask into this channel.

:)
retrocity


jasonmit posted Sun, 03 August 2003 at 12:01 AM

retrocity: Thanks for your help, but even opening images as layers is Greek to me. I guess I'll have to learn Photoshop better before I can do this.


retrocity posted Sun, 03 August 2003 at 9:49 PM

Hi jason, Photoshop will open most standard graphic formats (TIF, JPG, BMP, GIF...) so the easiest way to do this is to open Photoshop and open your images with the open dialog box. This will automatically create a layer containing your image.

retrocity posted Sun, 03 August 2003 at 10:06 PM

To add the second one to the same file, open it the same way and then select all ( SELECT --> ALL or Ctrl+A) This copies the image to the clipboard. Go back to the first image and paste (EDIT --> PASTE) this add a new layer on top of the first image.

retrocity posted Sun, 03 August 2003 at 10:12 PM

Now you can click on the Channels tab to switch over to channels and click on the arrow and select New Channel from the menu. This give you a blank channel. Open your mask image and copy this to the clipboard too and then paste it into the blank channel

Novacane posted Tue, 05 August 2003 at 12:55 PM

I've never understood this about Photoshop... why can't you simply copy and paste an image into a layer mask? The procedure that Jasonmit is attempting is something I've never succeeded in doing properly, and always ended up having to use a color range selection on the B&W image and then deleting from the image I wanted to mask. Retrocity, I tried following what you did there, but I ended up with a similar red picture to yours. How do you actually make the red area transparent? It seems weird that this kind of 2d compositing is far simpler to do in 3ds max. Even after effects handles alpha channels better.


Novacane posted Tue, 05 August 2003 at 1:21 PM

Out of curiosity, I checked to see if Paint Shop Pro could do it, and it turns out it does it the right way. What you do is open up all 3 images within PSP. Copy the image with the pillows you want to keep and paste it as a new layer (ctrl-L) on top of the other rendered image. Now, select the new layer and from the Masks drop down menu, select New - From Image. From the Source Window drop down, choose the B&W mask image. Leave "Source Luminance" selected (Source luminance will allow you to mask using shades of gray to produce varying degrees of transparency. Any Non-Zero Value will make everything that's not black 100% visible. You could probably use this setting, actually, if you're trying to remove anti-aliasing). Hit OK. That's it. The image I included just shows the pillows masked over a white background since in low res I can't tell which pillows were supposed to be non-antialiased.

karosnikov posted Wed, 20 August 2003 at 11:45 PM

the red layer is only in the " mask mode just click on the normal mode to exit quick mask , plus when you copy the image inot the mode you automatily get the right selction, ( i think pasting the black white into the quick mask will work ) then "delete the area"" you may have to stich from normal to quick mask and back just to get agrasp on what things you ar effecting on the layer..tip hide a layer you are not working on just so you can watch what happens to it. hehehe


karosnikov posted Thu, 10 August 2006 at 9:07 PM

edit...

 

 

the red layer is only in the " mask mode " just click on the normal mode to exit quick mask , plus when you copy the image into the mode you automatily get the right selction...   then "delete the area"  you may have to swich from normal to quick mask and back just to get a grasp on what things you ar effecting on the layer..tip hide a layer you are not working on just so you can watch what happens to the one you are working on