Objects with transparencies not combinging into bitmap properly

I have need to combine 2 objects into 1 bitmap.  Top image is a black (K 100) box with 50 tranpareny, bottom image is just a rectangle with red fill C 0 M 100 Y 100 0.  When I combine into 1 bitmap coreldrawx5 is dropping out colour.  Maybe using 'normal' rather than 'multiply'.  When viewing with proof colours turned on it looks like B) even before combining.  Looks like there must be a setting somewhere where Corel that controls how it combines colour of objects as it converts to bitmaps but for the life of me i cant find it.  Anyone help?   

A) Should be like this with combined         B) Converts to this with combined colour

colour of C0 M100 Y100 K50                       of C0 M50 Y50 K50.                             

                                 

    • Hi David,

      it appears to be a bug! If you convert to an RGB bitmap the colours stay the same, regardless of whether you use Normal or Multiply transparency mode. What you can do is convert to RGB bitmap and then click Bitmap>Mode>CMYK(32-bit) to convert it to a CMYK bitmap. This would involve 2 colour conversions, however...CMYK to RGB and then RGB to CMYK. This may or may not be an issue for you.

      Best regards,
      Brian.

      • Thanks for your replys,  yes I agree it's a bug but I think it's also a missing or over looked feature CDX5 needs.   Without proof colours turned on with CMYK printing profiles, this issue can be hard to see.  If you work in RGB this probably won't ever be an issue for you but the bug remains.

        In brief CDX5 assigns 'normal' merge mode to bitmaps (bitmap must have transparent background enabled to have a merge mode at all),  RGB or CMYK ,  and theres no way you can change it within CDX5. 

        This issue can arise in many ways.  It became an extreme issue for me when converting Corel Drop shadows that were over a solid red background to bitmaps.  Drop shadows converted to bitmap need to have muliply mode or the colour knocks out as described earlier but when saving as bitmap (with transparent background on) there is no way to select merge mode, the new bitmap is in normal mode even though the corel drop shadow had merge mode set.  It is lost when you save as bitmap.  Sancho Drop shadow sufferes the same fate, I select MP (multiply) as the shadows merge mode but rendered shadow does not have Mp merge mode.  Again you will need proof colours turned on with CMYK profiles to easily see it.

        You can find out what merge mode any bitmap has by selecting 'edit bitmap' and checking out its properties in PP.

        In PP you have the option to assign a bitmap any merge mode at any time by right clicking on bitmap and opening 'object properties' dialogue.  This should be an option in CDX5 as well as a selectable option when converting to bitmap.  To fix my issue with drop shadows in CDX5 with drop shadow bitmap selected click 'EDIT BITMAP'.  Once the bitmap is opened in PP right click on it - open object properties, change its merge mode from NORMAL to MULTIPLY save and exit.  Bitmap in CDX5 now has multiply merge mode.  It looks and prints properly.

        I converted this bitmap that definitely had merge mode to a bitmap again with tranparent back ground and it reverted to normal merge mode.  Proof that merge mode is being lost.

        So merge mode is lost (or reverts to normal)  when saving as bitmap, which is the bug, and there is no way in CDX5 to apply a merge mode to a bitmap either when converting to bitmap or through object properties, which is a missing feature.

         

        • This works really well when you are trying to export a transparent overlay on an image into one jpeg. the colour doesn't hold on the overlay when you export straight to a cmyk jpeg. If you convert the whole image into an RGB then convert again into a cymk you then can export it to a cymk jpg without losing the colour. (Sorry if this sounds confusing, but if you run into what I am, you will know exactly what I am talking about)