How to resize a pic with Irfanview

[Wurger]

BTW .. please note that the Irfanview adjust the pic size to the way the Panorama image is going to be created automatically. If it is the horizontal row the pic height is adjusted while for the vertical shot its width.

 

[Graeme]

Hi again mate.

Bizarre request I know - but I'm looking to see if I can improve on creating 'silhouettes' from line drawings with Irfanview. Line drawings from the internet don't seem to work as well as those scanned from publications - but I've struck one problem - which I think is thin paper?

Behold the Dagger from a scanned German publication...

Crop the line drawing - "sharpen" and apply "negative" - and it's looking OK...

But what I want to do now - is remove the black background. I'm trying with the "paint can" but it seems to recognise what is seen on the other side of the page (Convair C-131B in this case).

Any tips to defeat this?
Cheers!

 

[Wurger]

Like that ?

if yes ... open the black picture with the IrfanView and use the Image -> Negative option to make the image B&W ...

You should see all the unwanted pixels ...

having the B&W done use the Image -> Decrease Color Depth option ...

In the pop-up small window mark the Custom option and type the depth number ( 2-256) in the white rectangular. Please note that the three basic settings have already been prepared for choosing. The default setting is the 256. But the Custom setting gives more possibilites in getting the effect. I typed "8" there that seems to be enough. Then click the OK button. If you aren't happy with the final effect click the "Undo" arrow at the top bar and go back to the Custom value and try to use other one ( eg. 10 that seems to be OK either )

The final effect ...

If you think the final efect is fine but the pic is slightly too blurry , use the Image -> Sharpen option or just hit the Shift+S keys together once.

you should get the final image like the one ..

Finally use the Image -> Negative option again to make the pic negative. But having the clear B&W image you may paste it to the Word document or print with any printer.

Please remember of clicking of the Save button at the end to save your work.

 

[Wurger]

And here the entire page cleaned with the Decrease Color Depth option set for the 8 value. The pic was also double resized up.

 

[Graeme]

We're not quite on the same wavelength mate - not to worry.
I want to be able to turn any good line-drawing into a black silhouette with a WHITE background.

Example...

Line drawing...

Clean it up - using the method you described above...

Apply the "Negative - all channels"...

Now the difficult part - trying to remove the black background. The only method I can think of is using "Floodfill" from the paint box.
But this what I get and it's not very good - is there a better way of creating that white background?

Cheers!

 

[Wurger]

Ah ... now grasped. Just thought you wanted to clean the bacground. I haven't needed to make any pic that way. I have to think a little bit. But It may be quite difficult to do using the Irfanview. IMHO a more advanced graphic soft would be better.

 

[Wurger]

Unfortunately the problem is with the Irfanview that is the pic browser basicly. For the Irfanview there is one colour only and it treats them as the background one. As a result you may remove either the black or white fully. For the operation you asked there is needed a tool that is called the Magic Wand and possibility of working with layers. The such things are offered by the more advanced graphic programs. I have used the Photoshop and got the results in 5s. I think the GIMP has the same options available.

 

[GrauGeist]

You can also adjust the Saturation prior to using the Magic Wand.
I haven't used GIMP or Irfanview, but Photoshop and Paintshop have the same features.
Increasing or decreasing the background saturation will eliminate "artifacts" when selecting the background color with Magic Wand.

 

[Marcel]

You can also adjust the Saturation prior to using the Magic Wand.
I haven't used GIMP or Irfanview, but Photoshop and Paintshop have the same features.
Increasing or decreasing the background saturation will eliminate "artifacts" when selecting the background color with Magic Wand.

I can vouch for Gimp. Have been using it for over 10 years. It has 90% of the power of Photoshop but can be used legally for free. IMHO it's much better than Paintshop, the program I started out with in the first place.

 

[Wurger]

As usual that's a matter of habit, my friend. But undoubtedly the GIMP is a very useful free soft.

 

[Graeme]

Thanks Wurger - Marcel and Dave.

I haven't needed to make any pic that way.

Yeah, just a childhood interest that has persisted into adulthood.
Cheers....

 

[Wurger]