Mike Chaney's Tech Corner

I am pushing QImage into doing something it was probably not designed for...  namely, printing very accurate drawings for graphics arts purposes.  The print has to be pixel perfect (i.e., one inch in the image has to equal exactly one inch on paper when it is printed).

So I save a monochrome bitmap (BMP) image with 1200 dpi resolution, which I then place on a QImage page, as you would with any other image.

This brings me to the question:

When "Auto Crop" is turned on, the image is resized to fit whatever size I have chosen on the "Prints" tab - which is as I would expect.

However...  when I turn off Auto Crop by clicking the scissors with the image selected on the page, it is resized to something much bigger than it actually should be, at 300dpi...  it becomes 4x too large.

What I was hoping for was that the original resolution / size of the image would "survive" into the print on the QImage page, like a normal image does.

Is this some kind of issue with using monochrome bitmaps?  (It works perfectly in every other respect and prints beautifully when Auto Crop is on, but it is a pain to resize the Print every time).

Hi, in custom sizes, there is the option to print Original Size, use that.
However,  you may be expecting too much wrt precision when printing on paper, or any other media. There are other uncertainties that affect a print size. I use "uncertainties" as a technical quality control term!
In particular, the accuracy of the printer carriage positioning,  the paper feed and particularly the stability of the paper (media). I have found that high quality photographic paper grows about 0.012% which is significant on an A3 print.
You'll have to try it and see how you get on.
BTW. Re. print crop on or off. That is used when size is set in QU.  The aspect ratio may not match that of an image, so the image is cropped (not "resized") to obtain the desired print size. In you case, specifying the print size with crop off should give   the same result as using "original" size.
You have not said what size your prints need to be, pleas tell us.
Terry

Try this:
Open the print size box and select CUSTOM.
Then look at the upper right corner (Override BOX) Type in 1200 and put a check in Over ride. Screen snaps 002 and 003
Then OK. Back to the main screen, add your image, it will be 1200 ppi.
Terry called me to help. He is visiting and only has his smart phone. No screen snapper.
Fred

If you save a Tiff or Jpeg from Photoshop it has a virtual physical size attached. When you load these files (AFAIK) that describes the conditions where Qimage Ultimate correctly sets the 'Original Size' when 'Original Size" is selected for the image to print. Exports from other applications may not work out correctly, even Tiffs and Jpegs. Other file formats from Photoshop may not work either.

BTW, be aware that assigned color spaces may not work properly either with some image formats.  BMP can have an assigned color space as I understand it, the question is whether applications read that. For B&W work and greyscale files you would like to have the Gamma choice assigned.

I am not going to test what might and what might not work properly but restrict myself to what works and where I know it does not work correctly but does for me :-)


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots

Apologies for being so SLOOOW to respond to this!

Terry-M's trick of using "Original Size" on the print size is what was needed.

I'm printing on 24" roll paper.  The largest image I've printed with QImage is 24" by 96".  Awesome!   :)