click here for a list of all existing Templot documentation
TEMPLOT CLUB - this old web site is now  READ-ONLY

to post new messages, please go to

NEW WEB SITE - CLICK HERE       more info - click here


     you are not logged in  - Login | Join

    Recent Topics

Front Page  Search  My Account  Members   



                 maps - feedback wanted
     
 Start new topic   Reply blank   Printer friendly 
  Rate this topic  
AuthorMessage
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
1st message | this message only posted: 24 Nov 2020 21:31
 PM  Reply with quote  Reply blank 
from:
Martin Wynne
West Of The Severn, United Kingdom



view images in gallery
view images as slides

Please do not send requests for help direct to me via email or PM.

Post your questions on the forum where everyone can see them and add helpful replies.
I mentioned earlier that it is now possible to load the NLS historic 25"/mile maps as tiled maps. Which is great news -- it means maps of any size can be easily captured at maximum zoom without any restriction caused by your screen size, or need to align multiple captures. It will be in the next program update.

I have since discovered that the highest zoom level available as original tiles is level 18 for the 25" maps. The higher zoom levels available on the NLS web site are actually implemented by upscaling the image in the browser. This means of course that capturing higher levels than 18 doesn't get you any more detail, the same level of detail is simply being zoomed larger.

Most browsers use a resampling image upscaler to provide a smoother result than a simple stretch of each pixel.

Such resampling isn't available in Templot when zooming background shapes on the trackpad, because at the high zoom levels we normally need it would take forever and reduce the screen response to a slow crawl through treacle.

But the result isn't very pretty or comfortable to work over:

1. map tiles as loaded:


It can also be confusing -- see for example how the platform edge has merged with the rail above.

A few updates back I added a function to reduce the contrast of map images when working over them, which makes it a lot easier to see what you are doing -- here on the left:

2. low-contrast converted original:


But it still doesn't match the screenshot captures from smooth browser resampling.

So I have found some old resampling code from Anders Melander which could be used in Templot, as a one-time conversion on the background shapes. It's very slow, several seconds per tile, but only needs to be done once.

The difficulty is that there are 7 different resampling algorithms available, with varying degrees of smoothing and speed, and each one can have an adjustable edge-effect setting. Mostly they are optimised for colour photographs, rather than scans of historic maps, so the default settings are not necessarily the best for our purpose. And then in each case there is the degree of zooming to apply. An utter minefield of different settings which would take me forever to evaluate.

From which I need to select 1 or maybe 2 options to offer in the background shapes. Here are some examples. In each case the original as loaded tile is on the right:

3. "Triangle" interpolation only. This is similar to the browser resampling for zoom level 19:




4. "Triangle" interpolation with low-contrast conversion:



5. "B-Spline" interpolation only:



6. "B-Spline" interpolation with low-contrast conversion:



Answers on a postcard. Which if any of these image effects would you find the most comfortable to work over? In each case the original loaded tile is on the right.

I think my preference is for image 5. above -- notice the improved separation between the platform edge and the rail.

There are of course several other settings you might use at the same time -- Templot can also make a negative image, and there are other colour schemes for the templates.

The use of these NLS maps is getting more popular for track planning, so it would be worthwhile finding the optimum screen display for them. This would be optional of course.

It's a pity the 50" maps aren't available for the whole country, but it's great that we now have almost full coverage for the 25" maps.

cheers,

Martin.

__________
message ref: 31375

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
2nd message | this message only posted: 25 Nov 2020 09:14
 PM  Reply with quote  Reply blank 
from:
Phil O
Plymouth, United Kingdom



view images in gallery
view images as slides
Hi Martin,

I'm with you, I think version 5 is the best.

Cheers

Phil.
__________
message ref: 31379

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
3rd message | this message only posted: 25 Nov 2020 09:34
 PM  Reply with quote  Reply blank 
from:
Tony W
North Notts., United Kingdom

 

view images in gallery
view images as slides
Hi Martin.

I would second version 5.

Regards
Tony.

__________
message ref: 31380

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
4th message | this message only posted: 25 Nov 2020 11:41
 PM  Reply with quote  Reply blank 
from:
Martin Wynne
West Of The Severn, United Kingdom



view images in gallery
view images as slides

Please do not send requests for help direct to me via email or PM.

Post your questions on the forum where everyone can see them and add helpful replies.
Thanks for the feedback. A majority there for the "Spline" interpolation.

But not so fast. :)

To illustrate the minefield I'm in, if the upscaling is increased it's not so clear-cut.

Going up to 720x720 pixels per tile instead of 512x512, the preference maybe swaps to the less intense "Triangle" interpolation (3. below), and "Spline" (4.) is a bit too fuzzy.

To confuse the issue further I swapped to the "bright night" colour scheme for the template:




Zooming out to the more usual browser size, the differences are not so obvious. But we don't do track design at this level:



We could go higher than 720x720, but memory usage increases dramatically, and screen response speed suffers. Maps can easily have 100 tiles or more.

I can also have a fresh think about the low-contrast functions. Maybe with the more intense interpolations it would actually be better to increase the contrast, for a cleaner background?

It seems clear that it's worth doing something to improve on the original loaded tiles, but deciding exactly what to do is tricky. And that's just for the 25" maps. There are also the 50" maps to consider.

Time for a boiled egg I think. :)

Martin.

__________
message ref: 31381

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
5th message | this message only posted: 25 Nov 2020 13:44
 PM  Reply with quote  Reply blank 
from:
Phil O
Plymouth, United Kingdom



view images in gallery
view images as slides
Martin,

I think it will be a difficult decision. Would it be possible to have a hands on trial version, I don't think just looking at the pictures is a fair test, as we all tend to work differently and screen size may also play a part.

I am looking at your latest post on my tablet and the differences are not great, when I have finished lunch, I will have a look on the laptop.

Phil
__________
message ref: 31382

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
6th message | this message only posted: 25 Nov 2020 14:39
 PM  Reply with quote  Reply blank 
from:
Phil O
Plymouth, United Kingdom



view images in gallery
view images as slides
Martin,

I have checked the pictures on the laptop and the images are more or less the same, perhaps it may be that the map area covered by the Lower image is larger than the one above it.

Phil.
__________
message ref: 31383

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
7th message | this message only posted: 25 Nov 2020 18:00
 PM  Reply with quote  Reply blank 
from:
Martin Wynne
West Of The Severn, United Kingdom



view images in gallery
view images as slides

Please do not send requests for help direct to me via email or PM.

Post your questions on the forum where everyone can see them and add helpful replies.
Thanks Phil.

That's the problem, the different effects are going to vary widely on different screens.

Here's another idea, reducing to 2-tone greys:

 

Top left is original 256 tile reduced to 2-tone.

Bottom left is Triangle interpolation from 256 to 768.

Bottom right is Triangle interpolation from 256 to 768, followed by reduction to 2-tone. I think that might work quite well as a design guide.

The template is in bright-night colours.

In the end I'm probably going to have to do a full dialog with all these optional adjustments. But I was hoping to find a default setting which would give good results for most users in most cases.

cheers,

Martin.

__________
message ref: 31384

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
8th message | this message only posted: 25 Nov 2020 18:29
 PM  Reply with quote  Reply blank 
from:
Martin Wynne
West Of The Severn, United Kingdom



view images in gallery
view images as slides

Please do not send requests for help direct to me via email or PM.

Post your questions on the forum where everyone can see them and add helpful replies.
This is what that looks like in full:



And working over it (bright-night colours):



cheers,

Martin.

__________
message ref: 31385

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
9th message | this message only posted: 25 Nov 2020 19:20
 PM  Reply with quote  Reply blank 
from:
Phil O
Plymouth, United Kingdom



view images in gallery
view images as slides
That looks ok to me. Thanks.

Phil.
__________
message ref: 31386

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
10th message | this message only posted: 26 Nov 2020 01:32
 PM  Reply with quote  Reply blank 
from:
Rob Manchester
Manchester, United Kingdom



view images in gallery
view images as slides
Hi Martin,

"Triangle interpolation from 256 to 768, followed by reduction to 2-tone" looks way better for my eyes. But then again nobody else has my eyes :) or my muddled brain :(

Rob


__________
message ref: 31387

 
 Clicked a link? Wrong message? Wait until the page has finished loading, click in the address bar and then press the Enter key. This is a timing bug in some browsers.
11th message | this message only posted: 27 Nov 2020 15:58
 PM  Reply with quote  Reply blank 
from:
Martin Wynne
West Of The Severn, United Kingdom



view images in gallery
view images as slides

Please do not send requests for help direct to me via email or PM.

Post your questions on the forum where everyone can see them and add helpful replies.
Rob Manchester wrote: But then again nobody else has my eyes :) or my muddled brain :(

Nor mine. :)

I think I have given up on finding a single setting which gives the best results in all circumstances, there is too much variation in the original map sheets.

So I have created a full dialog, with defaults which should work reasonably well in most cases, but maybe not always:

 

The 2-toning can be set to any desired colours, not only greys, or can be set to match the trackpad colours for the different colour schemes. There is a slider to set the threshold level.

Now to finish writing the code, especially the idiot-proofing for when I click the wrong thing. :?

cheers,

Martin.

__________
message ref: 31392

 
This is topic ID = 3823     Page created at 05:39 (local time)  
You can type a quick reply to this topic here.

Click in the box to begin.


But to reply to an individual message, or to include images, attachments and formatted text, use the reply buttons on each message above.

To start a new topic in this forum, click the Start new topic button below.
To start a new topic in a different forum, click the Forum Jump drop-down list below.

             Start new topic 

 click to jump to a different forum:     Back to top of page

Templot Club > Forums > Templot talk > maps - feedback wanted
about Templot Club

list recently active topics Templot Companion - User Guide - A-Z Index Templot Explained for beginners Please click: important information for new members and first-time visitors.
indexing link for search engines

back to top of page


Please read this important note about copyright: Unless stated otherwise, all the files submitted to this web site are copyright and the property of the respective contributor. You are welcome to use them for your own personal non-commercial purposes, and in your messages on this web site. If you want to publish any of this material elsewhere or use it commercially, you must first obtain the owner's permission to do so.

The small print: All material submitted to this web site is the responsibility of the respective contributor. By submitting material to this web site you acknowledge that you accept full responsibility for the material submitted. The owner of this web site is not responsible for any content displayed here other than his own contributions. The owner of this web site may edit, modify or remove any content at any time without giving notice or reason.
Problems with this web site? Contact webmaster@templot.com.   This web site uses cookies: click for information.  
© 2020  

Powered by UltraBB - © 2009 Data 1 Systems