[comp.graphics] MacPaint Question

chrisb@hubcap.clemson.edu (Chris Behrens) (06/13/90)

After using PBM Plus, how do I make my resulting MacPaint file
viewable on my Mac ???   White icons do not show up in the file
selection box.
Also, When viewing these same mac pics on my IBM using Optiks,
some larger images seem to be missing the header, or have an extra
one. (the picture is split so the right and left sides are swapped,
or some of one side is on the other.) 
Is there a way to solve this ??? 
The files I am using originate as BitMaps from the Poskanzer collection.
After a xbmtopbm, and pbmtomacp conversion with no flags, this occurs.
Any Ideas ??

Chris Behrens   ChrisB@Hubcap.Clemson.Edu

efwjr@bam-bam.paradyne.com (Ellsworth Warmouth x2882) (06/14/90)

In <9330@hubcap.clemson.edu> chrisb@hubcap.clemson.edu (Chris Behrens) writes:

>After using PBM Plus, how do I make my resulting MacPaint file
>viewable on my Mac ???   White icons do not show up in the file
>selection box.

To get these documents to show up as MacPaint files you have to change
the Type Descriptor for the file to PNTG and you may also want to change
the Creator Descriptor to MPNT.  I do this with a DA called File Tools
but you can also change it with other tools like ResEdit.  This will get
the Mac to recognize the document as a painting (PNTG) with the creator
being MacPaint (MPNT).  Of course you may want to have a different
creator than MacPaint if you don not have this program on the Mac and
you are viewing the results with a different application.  File Tools
can tell you what is the creator type for your application if it is not
MacPaint.

>Also, When viewing these same mac pics on my IBM using Optiks,
>some larger images seem to be missing the header, or have an extra
>one. (the picture is split so the right and left sides are swapped,
>or some of one side is on the other.) 

I have this same problem only reversed on the Mac.  This is due to the
fact that most PC display tools use the readmac format.  This is simply
a Macpaint document with a header that is created when you BINHEX the
Mac file.  BINHEX is a standard Mac interchange format usually shown as
.HQX.  This format is intended to solve the problem of transmitting the
Resource Fork, the Data Fork, and the File Descriptor information
including the Creator and the Type descriptors as described above, along
with the lengths of these various portions.  It also is intended to
convert all of the 8 bit information into 7 bit information so it can be
transmitted over modem networks.  Since the MacPaint format uses only 7
bit information, the image is not encoded in the .HQX format only added
to the file.  The readmac software needs the header to find out the size
of the image, when this header is not appended, the image does not look
normal on a PC.  On the Mac side if you display an image without
decoding the header with BINHEX, the image will also look abnormal since
the Macpaint software only needs the raw data and the header only causes
problems with displaying the picture.

>Is there a way to solve this ??? 

Use FileTools or some other program to change the descriptors for
viewing on the Mac side.  Run the resulting file through BINHEX before
sending the file to the PC.

>Chris Behrens   ChrisB@Hubcap.Clemson.Edu

Ellsworth Warmouth AT&T Paradyne Largo, Fl  efwjr@pdn.paradyne.com
I only speak for myself and not AT&T Paradyne.