Converting PCL to TIFF

[GeneralHQ]

We have been using ImageMagick successfully for some time now to convert TIFF images to PCL, using the Magick++ interface.

Now we are trying to do the opposite - take PCL data and convert them to TIFF images. However, whenever I try to read the PCL data in, I am getting an error.

First I create the PCL data in memory, then create a blob with that data. The error occurs when I execute an Image.read(blob) instruction, where I get an exception saying "ImageMagick: PCL delegate failed".

My question is, does ImageMagick allow me to do what I am trying to do? Can I use PCL data as input to create an ImageMagick image? If it does have that capability, what could be causing this error?

Thanks,
Robert

[magick]

Some image formats in ImageMagick require external delegate programs to work. To interpret PCL, you must first install GhostPCL.

[GeneralHQ]

Thank you. That seems to have gotten me most of the way there, but I still have one (well, two) more question(s).

I have downloaded and installed GhostPCL and seem to have it working to get ImageMagick to now read my PCL data to do the conversion needed.

The problem I am facing now is that the conversion is done at 72 dpi, which is a very low resolution. I would like it to be read in at 300 dpi. This appears to be done when I do my "Image.read( blob ) ;" command.

Looking at the ImageMagick delegates.xml file, I see a line to take PCL images and specify PCL6.exe (ie GhostPCL) along with a bunch of parameters to handle these files. One of the parameters is "-r%s". It is that %s that is apparently gets replaced by ImageMagick with "72x72". If I edit that line and replace it with "r=300x300 -sfoo=%s", it seems to work as I would like, by specifying 300 for the resoultion, then a garbage parameter -sfoo= to absorb and ignore the 72x72 that ImageMagick will replace the next %s with.

My question is ... How do I get ImageMagick to specify 300x300 instead of 72x72 as the -r parameter value used to invoke GhostPCL, so that I don't have to edit the delegates.xml file with this hack? What setting am I missing in ImageMagick that specifies that resolution value?

Also, when I do the Image.read( blob ) command, I am getting a warning thrown from ImageMagick saying "unknown field with tag 292 (0x124) encountered. 'TIFFReadDirectory'". That warning seems to be normal and the rest of the code works fine if I ignore it, but I was curious why I am getting that warning and if there is a way I can get rid of it.

Thanks,
Robert.

[magick]

Use density() to set the resolution before you read your PCL image.

[GeneralHQ]

Thank you. The density() was just the tip I needed. And let me also say that you all run a great forum here. Very helpful and professional with fast and accurate answers. Thank you so much for that.

One last issue, and then I think I've got it all my code working right.

The TIFF image I'm creating has Tag 262 - Photometric Interpretation - set to 1, and for our system we'd like to have it set to 0. How do I do that, using the Magick++ interface?

I see documenation on the convert command referencing -define quantum:polarity=min-is-white or min-is-black ... to set it using the convert command line tool, but I'm using the Magick++ interface, not a command line interface.

Thanks.

[magick]

Use defineValue().

[GeneralHQ]

What paramters am I supposed to give to defineValue()?

I tried:
image.defineValue( "quantum:polarity", "min-is-white" ) ;
image.defineValue( "262", "0" ) ;
image.defineValue( "TIFF", "quantum:polarity", "min-is-white") ;
image.DefineValue( image.magick(), "quantum:polarity", "min-is-white");
and several other combinations thereof.

and no joy.

[magick]

Use image.defineValue( "quantum", "polarity", "min-is-black" ) .

[GeneralHQ]

THANK YOU!!! That is exactly what I needed to know.

I actually used 'min-is-white' (not 'min-is-black') as the third parameter to get the results I was looking for, but it works great.

I am now making TIFF images from the PCL exactly as I need them to be.

Thanks again. You guys are great!

[lamantin]

Hi,

I am really starter with Image Magick, I only found this program while i was google for my problem.
My problem to solve is to calculate the ink-usage (let's say ink coverage) of printing jobs (PCL5-PCL6). Could it be possible to convert PCL job to TIFF for example, and to gain the the black, magenta, yellow, cyan coverage?

Could somebody give a detailed description how to do this, and which "functions" of ImageMagick should I learn to use it.

Thank you in advance!