strange image printing issue (VCL)
strange image printing issue (VCL)
We've got a situation where users scan in some images and attach them to a "claim", which is a collection of database records. The main app only lets them scan in jpg and tiff files, and they can attach jpg, tiff, and txt files separately. These attached files are stored in a BLOB field in the DB record (it's an Oracle DB).
A separate program is used to go through the list of claims and print out any that are flagged to be printed. This whole process is working, more or less. But there's a quirk that has just been discovered. (Actually, it seems that it has been around quite a while, but nobody reported it.)
Sometimes, some of the scanned images will be printed in a "magnified" or "zoomed" fashion. So, for example, most cases seem to take the upper-left 1/4 page of an image (typically a normal letter-sized page) and double its size, filling the printed page with this zoomed 1/4-size image. This happens for reasons we have yet to determine, but it's rare -- maybe 3-5% of the claims that have attachments end up printing them "magnified" like this.
We've also been told that sometimes the section of the original image that's "zoomed" is from another place on the page, often the center. And sometimes it's rotated 90 degrees so it shows up as if it's in Landscape mode.
So here's the really weird part: if we go into the DB and pull up the records that have these attachments stored as BLOBs, we can view them and they look perfectly fine! We see the whole, normal, unzoomed page image. But the app that's printing them is zooming them.
Both apps are written in Delphi (D7) and use the same libraries.
This is not random, either. The same images that print zoomed ALWAYS print zoomed, and the others are fine.
We haven't found a pattern yet, although we've asked the people who are doing the printing to start keeping a log of all of the mis-printed pages, and make a copy of them so we can see what variations exist.
Also, we can view an attachment in PL/SQL that looks normal but prints zoomed, and then print it to a PDF file, and even the PDF rendering is zoomed! (We've tried three completely different PDF rendering engines.)
My question to the mob here is this: is it possible that something in the image file headers could be causing this strange behavior at print-time?
Is there anything else non-visible (ie, metadata) that's worth investigating?
We've got a situation where users scan in some images and attach them to a "claim", which is a collection of database records. The main app only lets them scan in jpg and tiff files, and they can attach jpg, tiff, and txt files separately. These attached files are stored in a BLOB field in the DB record (it's an Oracle DB).
A separate program is used to go through the list of claims and print out any that are flagged to be printed. This whole process is working, more or less. But there's a quirk that has just been discovered. (Actually, it seems that it has been around quite a while, but nobody reported it.)
Sometimes, some of the scanned images will be printed in a "magnified" or "zoomed" fashion. So, for example, most cases seem to take the upper-left 1/4 page of an image (typically a normal letter-sized page) and double its size, filling the printed page with this zoomed 1/4-size image. This happens for reasons we have yet to determine, but it's rare -- maybe 3-5% of the claims that have attachments end up printing them "magnified" like this.
We've also been told that sometimes the section of the original image that's "zoomed" is from another place on the page, often the center. And sometimes it's rotated 90 degrees so it shows up as if it's in Landscape mode.
So here's the really weird part: if we go into the DB and pull up the records that have these attachments stored as BLOBs, we can view them and they look perfectly fine! We see the whole, normal, unzoomed page image. But the app that's printing them is zooming them.
Both apps are written in Delphi (D7) and use the same libraries.
This is not random, either. The same images that print zoomed ALWAYS print zoomed, and the others are fine.
We haven't found a pattern yet, although we've asked the people who are doing the printing to start keeping a log of all of the mis-printed pages, and make a copy of them so we can see what variations exist.
Also, we can view an attachment in PL/SQL that looks normal but prints zoomed, and then print it to a PDF file, and even the PDF rendering is zoomed! (We've tried three completely different PDF rendering engines.)
My question to the mob here is this: is it possible that something in the image file headers could be causing this strange behavior at print-time?
Is there anything else non-visible (ie, metadata) that's worth investigating?
Can you save the problematic images separately for close examination? Can you make statistics?
ReplyDeleteFor example JPEG/JFIF format poctures may have EXIF/IPTC tags which can specify proper rotation and proper phisycal dimensions. It can happen that printing service reads those instructions and follows them.
Maybe TIFF format can have tags with simikar purposes too.
Yes, I'm waiting to get copies of a couple of the known culprit files and I'll look at the headers.
ReplyDeleteAttila Kovacs the area that prints is more than 1/2 ... it looks closer to 2/3 of the original page width. Not sure about HT.