Grotty Image Advice

[Tipton Harrier]

Guys

This is a small area from a grotty scanned copy of a newspaper cutting I am trying to 'improve'. I do not have the original paper copy. Could anyone suggest the best approach to remove the imperfections? I have a few like this to address.

[BoltBait]

Effects > blur > Gaussian Blur (radius 2)

Effects > noise > Median (radius 3)

[davidf]

I felt like a challenge, so I made a plugin that you can use to (kind of) improve the image ... here are the results:

Before using the plugin, you need to scale the image by half, since the original is made up of 2x2 blocks. Use Image > Resize with a value of 50%. Make sure you set the resampling method to Nearest neighbor so no grey values are introduced; the plugin expects only black and white images.

Then run the plugin twice in a row; the second time, untick the box called "First pass".

The result still isn't all that perfect, since there is a kind of checkered effect in places that makes it hard to distinguish the background from the letters -- but I hope this is still helpful!

The plugin appears in the Effects > Noise > Fix Scan menu.

Download: FixScan.zip

There are instructions for installing plugins here: http://boltbait.com/...lingEffects.asp

David

Edited November 21, 2012 by davidf

[Ego Eram Reputo]

@davidf - are you going to release this plugin more formally?

(you should be thinking about compiling your plugins into a plugin pack - with it's own thread )

[davidf]

@davidf - are you going to release this plugin more formally?

It's pretty specialised at the moment, and the results aren't all that great, so probably not ... though I might have a try at something more general one day.

Doing this has given me a fresh appreciation of how good humans are at text recognition! There are some subtle things that are hard to detect with a computer program.

[Ego Eram Reputo]

I'm not sure how you're coding this effect, but have you met GetBilinearSample? I'm sure you would find it useful for this plugin.

See http://forums.getpaint.net/index.php?/topic/8419-displacement/#entry131337

[davidf]

I'm not sure how you're coding this effect, but have you met GetBilinearSample?

Lots of special cases -- I'm looking for patterns of pixels and then inverting some of them.

Does bilinear sampling introduce new colours (grey levels)? In this plugin I'm sticking to black & white ...

Edited October 18, 2012 by davidf

[Ego Eram Reputo]

To be honest I'm not absolutely sure.

As far as I understand it, it takes two (more ?) samples instead one (usually src[x,y] ). Whether it averages RGB or returns greyscale I'm not exactly sure.

Having got myself in over my head - perhaps I'll leave function of GetBilinearSample to someone who knows more about it!