Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
I suppose your inputs are vector, perhaps including text. "Convert" will take every page of each input, rasterising each page (ie converting the page to an image of dots). For the output, it combines all of these raster images into a single pdf.
IM is a raster image processor. If all you want to do it to append each input pdf into a single output pdf, it is the wrong tool for the job.
snibgo wrote:I suppose your inputs are vector, perhaps including text. "Convert" will take every page of each input, rasterising each page (ie converting the page to an image of dots). For the output, it combines all of these raster images into a single pdf.
IM is a raster image processor. If all you want to do it to append each input pdf into a single output pdf, it is the wrong tool for the job.
My inputs are raster images.
What is "IM"? Is it Imagick or a command/executable?
snibgo wrote:Yes, IM is an abbreviation of ImageMagick.
Tim wrote:My inputs are raster images.
In that case, perhaps you are not using the correct "-density" setting before each PDF.
I remember I read it somewhere that -density only specify the spatial resolution, and it shouldn't degrade the iamge quality. Correct?
Or do you mean the density used for re-rasterizing the individual pdf files? If yes, how shall I figure out what density is used for combine the individual pdf files?
Perhaps it might be useful for you to identify the version of Imagemagick, Ghostscript delegate that is being used for PDFs and your platform. You may need an upgrade to Ghostscript or IM.
fmw42 wrote:Perhaps it might be useful for you to identify the version of Imagemagick, Ghostscript delegate that is being used for PDFs and your platform. You may need an upgrade to Ghostscript or IM.
Also it might be useful for you to post the first 3 or 4 pdfs to some place like dropbox.com and put their URLs here so one of us can try duplicating your problem. Also what do you mean by degraded? In size, in sharpness, in color?
6.6.9.7 is ancient. IM is now at 6.8.9.10, so you are about 200 versions old.
The problem with raster pdfs is that the resolution of the image in the pdf may be different from the resolution of the vector shell of the pdf. That makes it hard to combine and maintain good "quality/resolution", unless you extract the images first and then combine them into one final pdf. IM cannot extract the image from a pdf, so you need to find some external tool to do that. They do exist.
fmw42 wrote:Also it might be useful for you to post the first 3 or 4 pdfs to some place like dropbox.com and put their URLs here so one of us can try duplicating your problem. Also what do you mean by degraded? In size, in sharpness, in color?
6.6.9.7 is ancient. IM is now at 6.8.9.10, so you are about 200 versions old.
by "degrade", I mean I can't figure out what words in teh part of 4.pdf corresponding to 3.pdf are no matter how much I zoom 4.pdf.
fmw42 wrote:The problem with raster pdfs is that the resolution of the image in the pdf may be different from the resolution of the vector shell of the pdf. That makes it hard to combine and maintain good "quality/resolution", unless you extract the images first and then combine them into one final pdf. IM cannot extract the image from a pdf, so you need to find some external tool to do that. They do exist.
I think you misunderstand:
There is no need to extract images from a PDF.
He has his images already: PNGs and JPEGs (of different sizes).
Tim wants to combine all his images into a single multi-page PDF.
fmw42 wrote:The problem with raster pdfs is that the resolution of the image in the pdf may be different from the resolution of the vector shell of the pdf. That makes it hard to combine and maintain good "quality/resolution", unless you extract the images first and then combine them into one final pdf. IM cannot extract the image from a pdf, so you need to find some external tool to do that. They do exist.
I think you misunderstand:
There is no need to extract images from a PDF.
He has his images already: PNGs and JPEGs (of different sizes).
Tim wants to combine all his images into a single multi-page PDF.
Sorry -- it's clear that I have misunderstood here
I confused this thread opened by Tim with the other one opened by Tim. Though, most likely, both threads deal with the same task he faces -- he originally had 250 PDFs, which he meanwhile converted to individual PDF pages...
