Precise scaling from your web browser

[lfuente]

Here's a neat thing I discovered about something that's literally in front of my nose!

Downloaders of my recolors will notice the optional print scaling instructions in case they want to downscale to common ratios (like 1:100, 1:144, 1:200, 1:250 and 1:300). But paper size specifications sometimes means having to settle for approximate scaling.

This came about as I had problems with Adobe Reader opening some old PDFs that needed Japanese language support, and noticed they opened OK on web browsers. It turns out that web browsers like Google Chrome (my default) or Microsoft Edge (tested) have an additional print menu for PDF files they open.

To access this menu you need to click the printer icon on the open file, then click 'more settings', then click on the 'scaling' box that takes input as percentages. This is in addition to the 'pages per sheet' box that lets you select how many pages to print on one sheet. This is very handy to minimize wasted space on printouts - for example, to print Canon's 1:30 Jaguar Mk.II in 1:160 you might print at 30/160 or 19% with much wasted space. Or you could first select 16 pages per sheet, which gets you 30x4 = 120, and then a final tweak of 120/160 or 75% which maximizes the space used.

The previous discussion assumes you are using an A4 file of known scale to print at smaller scales to A4 paper. There's an additional step if the target paper size is US Letter, since Letter is wider but A4 is taller. Before applying the final scale percentage you need to adjust the multi-page scale by 97% (divide by 0.97) then divide that by the desired scale to get the final percentage.

There's also the option of saving to PDF instead of printing, but I noticed that every time you do so there is a noticeable degradation in graphics quality, so it's better to print directly from the original PDF. Finally, there's the feature missing from Adobe Reader which is the selectable 'black and white' (greyscale) print option, for an instant recolor (although a grey Jaguar is rather boring).

PS
Having used Pip's and Ringo's suggested image extraction website (Extract all images from PDF free online) I can confirm that it works really well, and generates PNGs with very minimal color aliasing. The free online version can only be used once per day.

[Laurence Finston]

Originally Posted by lfuente

PS
Having used Pip's and Ringo's suggested image extraction website (Extract all images from PDF free online) I can confirm that it works really well, and generates PNGs with very minimal color aliasing. The free online version can only be used once per day.

Another way of doing this might be the following: With `pdfseparate' you can divide a PDF file into multiple single-page PDF files. pdfseparate is part of Poppler: "Poppler is a PDF rendering library based on the xpdf-3.0 code base." Poppler

You can then load the file with the image or images you want into GIMP. Then, select the parts you want, eliminate the rest (text or whatever) and export to the format of your choice, JPEG, PNG or whatever. An advantage of this method is that a menu pops up where you can set various parameters, including ones that affect the quality of the output. I've only ever used the defaults and have had good results.

For scaling, it's possible to use TeX and dvips. For this, the image needs to be in Encapsulated PostScript format (EPS). This is like plain or "structured" PostScript, except that it contains information about the bounding box. There are various programs for converting other file formats to EPS, `convert' from Imagemagick, epspdf for converting PDF to EPS (CTAN: Package epspdf) or GIMP again.

Once you have an EPS file, you include the file `epsf.tex' in your TeX file:
\input epsf
Then you define the macro \epsfsize to set the scaling. For example, \def\epsfsize#1#2{#1} sets it to the nominal size, \def\epsfsize#1#2{.5#1} sets it to half size, \def\epsfsize#1#2{2.5#1} sets it to 2.5 times the nominal size, etc. You can also scale the x- and y-dimensions separately. It is also possible to rotate the image, at least by multiples of 90°. It might also be possible to reverse it, I don't know. This is all explained in the dvips manual.

Then you call \epsffile to include an image, e.g., \centerline{\epsffile{alhambra_207_006.eps}}

Then run Tex and dvips to generate a PostScript file or dvipdfmx to generate a PDF file. You could also generate a PDF file from the PostScript file using ps2pdf.

Of course, you can also scale the image in the first place with GIMP.

All of the packages I've mentioned are free software, you can install them on your own computer and there are no restrictions on how many times per day you can use them.

[airdave]

Ifuente is correct...this is an easy to use "Scale during printing" method.
But you still need to calculate the correct amount of upscaling or downscaling you need (as a percentage).

I opened a PDF file (that was already on my PC) with Chrome browser.
it also works with Brave and MS Edge...and Firefox.
*the window looks a bit different in Firefox, but all the same controls are there.

...

To repeat what was said (I've attached a screengrab to show the options)...

Right click the PDF on your system and look for 'Open with'
Then choose that, and select the browser from the list that appears.

On the top right, look for the printer icon and hit it.

The window that opens is all your options...
look down for 'More Settings' (and click it to open the More Settings dropdown)

Look down to 'Scale' and select 'Custom' from the choices.

You can now set a precise percentage (in 1 degree increments) upscaling or downscaling.

Custom Scaling doesn't affect the PDF...it just changes how it will print.
The output (from your printer) will be rescaled accordingly.

REMEMBER: if upscaling a print, you may need to upsize the paper sheet (if your printer can handle bigger sizes).
...

I made a quick rescaling chart (attached below), but because there are so many scales to choose from,
its impossible to include every one...so I added a few empty spaces, and you can add
your own commonly used resizes.
Just add the original scale of the model to the top of the chart...
and add the desired Scale to the left side of the chart.
Then put the necessary print percentage in the connectng square.