Tinting Bitmaps with Transparent Backgrounds

Abstract

I'd like bitmaps to maintain their transparent backgrounds after applying certain QuickTime Effects such as Tinting. PowerCADD 6.0.4 makes them opaque (solid white), how do I get around that.

Requirements

PowerCADD v6 (v6.0.4 or newer recommended), QuickTime 6.x (6.4 or newer recommended), Mac OS^? X 10.2.x (10.2.8 or newer recommended)

Background

It's important to remember what's really going on here. Once a bitmap is selected, and Apply Bitmap Effect is chosen, Apple's QuickTime takes over for everything including interface, previews, etc. In the current context there really isn't a way for EngSW to create a one button solution. However, that's not to say it's not possible given QuickTime is what's being accessed and there are likely a number of ways to set those hooks.

Just having the ability to call QuickTime and have transparent background and pixels that don't bleed and ,and , and... are all huge strides in the right direction. The current tools are certainly a quantum leap from what we have had in the past +12 years!

Versions of PowerCADD 6 prior to v6.0.4 maintained transparent (nil filled) bits after applying a Bitmap Effect (that is a QuickTime Effect). However, changes in v6.0.4 now renders the previously nil (transparent) bits as solid white but it's an easy fix to correct the problem.

What to do

Following is a picture of our understanding of the problem. Essentially you need to use the Apply Bitmap Effect a second time (i.e. once to apply a Tint or desired effect, another to restore the transparent background).

There are few methods to achieve the transparent background. Brightness and Contrast is one but it has the unfortunate effect of only being able to adjust in 1 unit steps and can, if not used carefully, lighten or blow out the entire image.

There are other Apply Bitmap Effects options (QuickTime Effects) which are worth exploring which can create a nil/transparent background without compromising the foreground image. Assuming you have already applied your desired Bitmap Effect (perhaps you applied a tint as shown in the example above), you then need to do this to clean up the background:

1. select the bitmap
2. choose Tool Menu > Apply Bitmap Effect
3. choose Filter > General Convolution
4. enter a value of 0.025 in the Field 1 (leave all other fields untouched)
• (note: we recommend a starting with a small value of 0.025, your particular image may require a larger value, it will depend on the specifics of your case. Generally, always start with a very small amount and work up.)
5. Press OKAY and the image is now rendered with a transparent background (see our earlier screen shot for an example of the results)

Here's a simple example of how the effects can be combined to integrate hand drawn graphics (e.g. Pencil strokes), then tint them using Apply Bitmap Effects in PowerCADD v6. The results can be fun.

TintedHandGraphics.jpg

Remember, start with small increments and if you are going to try and use the brightness and contrast settings to adjust the image be careful you don't 'blow out' your main image. Work in very small increments like +1 or +2 and look at the results carefully. While there may be cases when the color shift is minor or won't matter (after all the printer will adjusted the colors too), it's best to be careful. We recommend Convolution but it can be a bit daunting to look at that numbered dialog and figure out what it all means!

Enjoy and remember this is fun so treat it like that. Experiment!

We hope that helps
caddpower.com

------
If you found this article or the website in general to be helpful, educational or a time and money saver you can show your support. Thank you ~ Brian (huc) Huculak