Images in PostScript

Thread View: adobe.postscript.programming

7 messages

[T] Back to Threads [V] Tree View [G] Group Articles

7 total messages Started by Gigi_Marcu Fri, 18 Jul 2008 08:24

#299

Author: Gigi_Marcu
Date: Fri, 18 Jul 2008 08:24

7 lines
925 bytes

Hi!

I am kind of new in PostScrip programming (actually code generation from C) and I want to know if there are some kind of encoding of an image when you need to write what it contains in the .ps files.

Can I write the bytes it contains using hexadecimal numbers or is there some kind of encoding I have to do.

Thanks in advance!

Re: Images in PostScript

#300

Author: Aandi_Inston
Date: Fri, 18 Jul 2008 10:21

5 lines
955 bytes

PostScript is very flexible. You can use raw data (but many printers
will choke on this), simple hexadecimal, or a combination of filters
(such as LZW encoding then ASCII 85 conversion). 

Aandi Inston

Re: Images in PostScript

#301

Author: Gigi_Marcu
Date: Fri, 18 Jul 2008 12:48

2 lines
890 bytes

I have read something about LZW and ASCII 85 conversion and it seems like a little work, that i don't want to do for nothing.
Do you think the combination of filters is much better than simple hexadecimal?

Re: Images in PostScript

#302

Author: Aandi_Inston
Date: Fri, 18 Jul 2008 13:30

7 lines
970 bytes

The only reason to use ASCII85 rather than ASCII, and the only reason
to use LZW rather than nothing, is because it makes a smaller file.
The smaller file might get to the printer more quickly. LZW is more
work for the printer, so it potentially prints more slowly when it
arrives.

Aandi Inston

Re: Images in PostScript

#303

Author: Gigi_Marcu
Date: Fri, 18 Jul 2008 13:40

2 lines
546 bytes

I understand.
Thanks for the tips!

Re: Images in PostScript

#317

Author: David_Cristian
Date: Tue, 22 Jul 2008 10:22

10 lines
975 bytes

Hi

Tell me if i got this straight ...

If i have a jpeg image and i want to make it smaller i have to take the binary file that represent the picture and apply the LZW encoding, and after that an ASCII85 conversion.

Would tis work?
I ask this because i have already implemented this and I want to see I have any logical problem.

David

Re: Images in PostScript

#318

Author: Aandi_Inston
Date: Tue, 22 Jul 2008 10:29

9 lines
1206 bytes

>If i have a jpeg image and i want to make it smaller i have to take the binary file that represent the picture and apply the LZW encoding, and after that an ASCII85 conversion.

Well, that would produce a valid image but it would be larger than the
JPEG in most cases.

For most JPEG files you can use them directly, treating them as having
DCT encoding, then apply ASCII85.

Aandi Inston

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads