Separating A Mask From A Cropped Bitmap In CorelDRAW

When a masked bitmap is imported into CorelDRAW the bitmap and its vector mask are converted into a "cropped bitmap". A cropped bitmap is treated as a single object where the bitmap and its vector mask are inseparable when using CorelDRAW alone. There is no way to separate a vector mask from the bitmap unless you use another vector application as a "go between". If you are not importing an EPS or PDF file and intend to work with a bitmap and vector mask as separate objects, it is better to use CorelDRAW's PowerClip™ feature instead.

If you open an EPS or PDF file with a clipping path using the File > Import > PostScript Interpreted (EPS) filter or if you embed a bitmap image and crop it with the node editing tools, you may run into this situation. Other illustration programs (Deneba Canvas™, Adobe® Illustrator® or Macromedia® FreeHand®) treat a bitmap and its mask as separate objects when imported as an EPS or PDF file. This tutorial uses one of these other applications to separate a cropped bitmap into its vector and raster components.
Extracting a mask from CorelDRAW first involves exporting the image as a PDF file (Adobe Acrobat® Portable Document Format), then using Deneba Canvas, Adobe Illustrator or Macromedia FreeHand to extract the mask from the bitmap. Any one of these programs is used as a "go-between" application which will read the PDF file and allow the mask to be extracted and saved as a vector EPS file. This vector EPS file can then be imported or opened by CorelDRAW (as well as Deneba Canvas, Adobe Illustrator or Macromedia FreeHand). The following chart illustrates the method:

Once the bitmap image with its mask has been loaded into Deneba Canvas, Adobe Illustrator or Macromedia FreeHand, the mask can be extracted and saved as a separate object which can then be edited in CorelDRAW or any other drawing program.

Extracting Clipping Paths From Corel PHOTO-PAINT

There is one drawback with the way Corel PHOTO-PAINT 8 handles clipping paths. Corel PHOTO-PAINT 8 saves a path in a separate file in a proprietary format which cannot be read by either CorelDRAW® or any other application except for Corel PHOTO-PAINT. This prevents their being opened and edited directly by any other application (CorelDRAW, Deneba Canvas™, Adobe® Illustrator® or Macromedia® FreeHand®). An image can be exported as an EPS file with its clipping path. By opening this EPS file in Adobe Illustrator, the clipping path can be separated and extracted from the bitmap portion of the image.

Note: Corel PHOTO-PAINT 9 now saves the path in the same file as the image.

Extracting a clipping path from Corel PHOTO-PAINT 8 involves first saving the path in Corel PHOTO-PAINT 8, then exporting the image as an EPS file (the EPS format is the only format where the clipping path can be exported). Adobe Illustrator is used as a "go-between" application which will read the EPS file and allow the clipping path to be extracted and saved in a format which can be used by other applications. The following chart illustrates the method:

Once the image with its clipping path has been loaded into Adobe Illustrator, the path can be extracted and saved as a separate vector file which can then be edited in CorelDRAW, Deneba Canvas, Adobe Illustrator or Macromedia FreeHand. The path also can be copied into memory within Adobe Illustrator and pasted into an Adobe Photoshop® file as a path.

Below are the step-by-step tutorials which outline exactly how this is done:

Moving Clipping Paths Between Photoshop and Corel® PHOTO-PAINT

Adobe® Photoshop and Corel PHOTO-PAINT 8 are two image editors with the capacity for incorporating vector paths. You may want to use both applications on a single image (Corel PHOTO-PAINT 8 creates an excellent path from a selection mask [alpha channel] with a single click).
Exporting an image and its clipping path from Corel PHOTO-PAINT 8 to Photoshop involves first saving the path in Corel PHOTO-PAINT 8, then exporting the image as an EPS file (the EPS format is the only format where the clipping path can be exported). Adobe Illustrator® is used as a "go-between" application which will read the EPS file and allow the clipping path to be copied and pasted into Photoshop via memory. The following chart illustrates the method:

Moving an image with its clipping path from Photoshop to Corel PHOTO-PAINT 8 requires no special steps. Corel PHOTO-PAINT 8 will open a native Photoshop .PSD file directly and any embedded paths are accessible from within Corel PHOTO-PAINT 8.

Below are the step-by-step tutorials which outline exactly how this is done:


Moving a clipping path from Photoshop to Corel PHOTO-PAINT 8:

1. Within Corel PHOTO-PAINT, click File > Open. Load the Photoshop .PSD file with the embedded clipping path.



2. Click the pull down next to the "WorkPath" on the tool bar or double-click the Path Node Edit Tool to bring up the Tool Settings and Click the pull down next to the "WorkPath" on it. You will see the path name of the embedded path. Click it.



3. The path will load and it is available for editing.

Porting Masked Bitmaps Between Illustration Programs

Whereas the best format to port straight vector files is generic EPS, I have found that the most reliable format to port a bitmap image with a vector clipping path or mask is PDF (Adobe® Acrobat® Portable Document Format). There is more than one format you can use to successfully port masked bitmaps between applications but I think that the format that works most reliably and consistently between Deneba Canvas™, Adobe Illustrator®, CorelDRAW® or Macromedia® FreeHand® is PDF.

Note: There is one proviso to using PDF as a means to port vector images and that is if you are using the RGB color space, you should use "Save As" or "Export" from Deneba Canvas Adobe Illustrator, CorelDRAW or Macromedia FreeHand to create the PDF file. If you use the "Print" output channel (such as when using Adobe Distiller®) all the RGB data may be converted to CMYK in the process - depending on the version of Acrobat. Refer to the Adobe technical document number 320683 at their web site: http://www.adobe.com/supportservice/custsupport/SOLUTIONS/15c32.htm

Porting a masked bitmap involves using either File > Save As (for RGB) or File > Print (for CMYK) as an output channel. A PDF file is generated by the File > Print command where the output is sent to FILE instead of the printer. These files are then transformed into PDF format through the use of Adobe Distiller. The PDF file can then be imported into the target application where the masked bitmap will be available for editing.

Below is a chart which illustrates the use of the Portable Document Format as a means to port masked bitmaps between Deneba Canvas, Adobe Illustrator, CorelDRAW or Macromedia FreeHand:

Below are the step-by-step tutorials which outline exactly how this is done:

Porting a Masked Bitmap From Macromedia® FreeHand 8®

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You can create a masked bitmap in Macromedia FreeHand 8 by importing a bitmap then using the pen to make the mask. This tutorial outlines the steps to export the masked bitmap as a PDF file.

1. Launch FreeHand 8 and File > Import command to embed or link a bitmap image, then create the mask with the pen. This is what the image looks like with nothing selected:



2. Click View > Keyline to view the mask:



3. Click File > Output Options, then uncheck "Convert RGB to process" since this example is an RGB image. Select a flatness of 3 so the mask will conform closely to the curves.



4. Click File > Print. In the print dialog select the Distiller® Assistant printer driver, then click the "Setup" button.



5. In the Separations tab select "Composite".



6. The output options (in step 3 above) are also available on the Imaging tab. Click "OK", to return to the print dialog, then click "OK" to print.



7. Distiller prompts you for a filename. Enter a filename or accept the default, then click "Save".

Porting a Masked (Cropped) Bitmap From CorelDRAW

In CorelDRAW 8 you may have a cropped bitmap image either by importing an EPS file with an embedded clipping path (using File > Import > PostScript® Interpreted [EPS]), or by loading a bitmap image and using the node editing tools to create the cropped outline. This tutorial outlines the steps to export the cropped bitmap as a PDF file.

Note: When an EPS image with a clipping path is imported into CorelDRAW, it is defined as a "cropped bitmap" where the bitmap and its mask become a single object. CorelDRAW also has a "PowerClip™" feature which is equivalent to a clipping path or mask in other drawing programs where the vector mask and bitmap image are separate objects. see Table of Equivalent Terminology

1. Launch CorelDRAW 8 and either load the cropped image or load a bitmap and use the node editing tools to create the cropped outline. This is what the image looks like in "Normal View":



2. Click the pulldown on the toolbar to change to "Wireframe View". This will reveal the cropped outline (mask).

Note: At this point it would seem that the most straightforward method of creating a PDF would be to use "File > Save As" or "File > Export" and choose the PDF file type. However, it has been my experience that Adobe® Acrobat® Distiller® produces the most consistent results for this purpose.

3. Click File > Print to reveal the humongous print dialog. You need to check all the settings that can affect the masked bitmap. First select the Distiller Assistant printer driver:



4. In the Separations tab, make sure the "Print Separations" check box is unchecked (we want a composite color output):



5. In the PostScript tab, there is a check box for "Output color bitmaps in RGB".  In this case we want to make sure the bitmap gets printed as RGB. Also notice the check box for JPEG compression. Make sure this is not checked. The "Set flatness to:" is set to 1 in this example. This is the setting for the mask. The lower the number, the closer the mask will conform to the curves.



6. In the Miscellaneous tab there is a whole bunch of stuff to check. In the "Special settings" section there is a scrolling box with a lot of options. Notice the one: "Print bitmaps as RGB". Next click the "Set Profiles" button up there on the right...there's no way around it...this is an Advanced tutorial.



7. For now let's not use any color profiles. Make sure the composite printer profile is set to "None". This relates to step 4 above. If we had wanted separations, you would check the profile for the separations printer. Click "OK" then click the "Print" button when you return to the Miscellaneous tab.



8. FINALLY! Distiller prompts you for a filename. Enter a filename or accept the default, then click "Save".

Using Masks in Illustration Programs

A mask is a vector path which allows part of an object to show while blocking out the rest effectively making part of it transparent. A mask in an illustration program is functionally equivalent to a clipping path in an image editor (more).

1. Take for example a photo. You can create a mask which will knockout the background.



2. Using the Pen, draw a path around the bird in the photo.



3. This is a view of the path only.



4. When the path is made into a mask and combined with the background image, the background becomes transparent.



5. Masks can be made to create many kinds of effects. A type mask can be combined with a background photo.



6. This is the mask created by converting type to curves.



7. This is the type mask when combined with the background image.