Rick's b.log - entry 2015/11/09

Printing with Ovation - don't use sprites

Don't use sprites!

DO NOT USE SPRITES IN YOUR DOCUMENTS!

I cannot stress that enough.

Look, here, consider this example file. The image is a picture of the SciCalc window.

I cannot offer you a copy of the PDF that was generated when the picture was a sprite file. This is because the PostScript driver spat out this monstrosity...

What went wrong? It's simple. The Acorn era PostScript driver is somewhat crap and will render sprites by generating an appropriately sized square object for each pixel of the image.
I really wish I was messing with you.
But I'm not.
The picture is 400×239 and it appears twice. That means there may be approximately 191,200 (no, that's not a typo - a shade under two hundred thousand) squares in the PostScript file. This explains the huge PostScript file, and probably why GhostScript pooed itself.
Probably just as well. Can you imagine sitting there while Adobe Reader on a tablet redraws all that rubbish?

What can be done?

There are two options. The commercial option is Martin Würthner's PostScript 3 driver (£35 / €40) which is greatly enhanced over Acorn's older drivers.

The non-commercial (free) option is to use JPEGs. JPEG images are passed to the PostScript file as JPEGs, and are converted to PDF more or less intact. Rendering speed is retained, a JPEG is a JPEG...

But, wait, aren't JPEGs lossy?
Yes, they are. However these effects are mostly invisible if you set the quality in your originating program to be 95%-98%. Keep the quality high. Of course, it would be better to be able to use a proper original bitmap, but not when this means hundreds of thousands of tiny fragments...

Don't take my word for it - here's the above document as a PDF: print_jpeg.pdf (113KiB). The window content used in this document was grabbed with Snapper exporting as JPEG, with JPEG quality set to 95%.

Oh noes!!1!11! It's all gone horribly wrong!!1!ONE!

And it looks rubbish?

This is easily fixable.

Go to PrintPDF's Choices... (iconbar menu) and select the Optimisation "Custom...".

In the window that appears, ensure the image compression is Flate (and not JPEG). Do it for all three types. Also, make sure the image downsampling is not active.

Now, documents will be printed with the images not compressed to hell and back, like this:

Note: You could also choose to untick all of the Image compression options; however this appears to make a file twice the size (using the test document) with no noticeable difference in output...

Creating runaround text

Consider this document:

Now, the big poppy drawing is a DrawFile that I knocked up. This process requires DrawFiles and not bitmaps because you will need to have transparency. You might have some joy with MW's PostScript 3 driver and sprites with masks, but this isn't something I can try (as I don't have the driver...). Leave a comment below if you do and it works.

Anyway. Here's the cheat close-up with the image hidden:

What I did was to create a picture frame (for the poppy) from the main text frame. This becomes the top-most frame and could straddle both columns.
I placed the poppy drawing inside the frame, and then set the frame to be transparent.
This caused all of the text to reflow back as if the frame wasn't there.
So I then created small text frames within the text column. This is important - as these new frames become "children" of the text column frame and lie underneath the poppy frame. The little text frames, and there are numerous, were sized and dragged into place to 'repel' the text. Careful placing allows the text to be repelled on a profile that more or less matches the poppy. Obviously I spent about ten minutes on this to show you the idea. A bit longer would lead to even more pleasing results.
The result isn't bad - poppydoc.pdf (13KiB) - there are a few things that could be tidied up (left: comma after "nibh" at top; "at" at bottom; right: "turpis" line to "Pellentesque" line should be indented differently; ditto for "tortor" line to "eget" line), but it serves to illustrate the point.

Going beyond

How it was made:

• On top of the main text frame, a picture frame containing a suitable explosion. This is an image from Wikipedia, from the UK-Grable nuclear test (Nevada site). As a US government work, it is in the public domain. The scale to fit didn't quite fill the frame, so it was manually bumped up a little and the picture dragged with the mouse until the frame was completely filled.
• On top of that, a text frame containing the title text in Nottingham font, 68pt, bold. Various colours for effect. The "vol.42" is 36pt and horizontal scale 80% to fit it in. The space between "WEEKLY" and "vol.42" is horizontal scale 40% as the text can slide a little closer to the 'Y'.
• The "EPIC BANGS!" is Ocarina.Bold.Condensed at any point size (doesn't matter). It is actually a DrawFile with the text rotated 90°. This DrawFile is then placed into a transparent picture frame, moved into position, and scaled to fit.
• The picture frame does not fill the full height of the page (otherwise scale to fit looks a bit silly with a tall narrow mushroom cloud), so the space at the bottom is a black frame with white Homerton 18pt bold text to highlight all the goodies inside the magazine.
• The barcode was made in Draw, dropped into a picture frame (with standard white background) and then dragged into the desired place.

Your comments:

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David Pilling, 11th November 2015, 22:05

Need Acorn PS level 2 driver for JPEGs. ISTR exploding sprites into pixels for printing only applies to some sprites. Certainly ones with masks (transparency), maybe also ones with more than 8 bits per pixel.    Yes it is a mess, which is why Martin W did the level 3 driver.

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