I am vectorizing the map, but it really takes time to trace all these contours in semiautomatic mode.
I tried autotracing but there is a problem with the thematic layer - the contours are spotty
because of low-quality printing.
Is there any way out?
File: 600 dpi, TIFF, 24 bit.
Thanks.

ET 8.7 can extract lines even from the 3.jpg image attached to the post although it is
JPEG 300 DPI (not at all TIFF 600 DPI 24 bpp!).

Lines in such an image looks like that:



And here is the result of extraction:



After automatic vectorizing and break-up joining we have:
(without any editing of vector before joining!)



P.S.

I didn't write about 7.99 knowingly as you had mentioned about another source image:



To process the enclosed fragment in 7.99, we will have to resample it up just to 600 DPI. So, I'm waiting the image you wrote about.

Thank you for attention to my question.
I tried v. 8.7 Demo and read about, I would buy it were I my boss.

The "right" image is too heavy (1.2 MB) - it's beyond limitations of your site.

Just cut off an acceptable area from the source image:
Edit->Crop->Rectangular

Processing tecknique does not depend on image size

Done - here is the scrap.

P.S. I suppose your website does not support displaying of TIFF format.

I have spent some time on the image (300 DPI, JPEG) attached to the first
post. Look at the result.
You may try to get it by yourself as the project is attached.
The quality of source lines is shown well in the second post.

First of all, I created a new project based on the image 3.jpg. Coordinate
units are pixels, coordinate origin – in the lower left corner of the image
(I do not go into matters of correction, transformation, georeferencing, etc.).

Then I opened 3.jpg, saved it as 3_relief.tif and added to the project.

After that, 3_relief.tif was treated with a sequence of raster editing operations.
The aim was – to blur and delete sepia points and to enhance contrast
and homogeneity of relief contours.

Note – red and green tints predominate in lines of relief whereas blue
is minor.
It was important to have it in mind at histogram-based mask selection
for Binarization.

The sequence of operations before Binarization comprised
(see 3_relief.LOG in the project archive):

------------------ 3_relief.tif ------------------

1. Image 3_relief.tif changed:
Diffuse :
Factor = 50
Radius = 1

2. Image 3_relief.tif changed:
Unsharp Mask :
Factor = 200
Radius = 4
Threshold = 0

3. Image 3_relief.tif changed:
Diffuse :
Factor = 50
Radius = 1

4. Image 3_relief.tif changed:
Unsharp Mask :
Factor = 200
Radius = 4
Threshold = 0

5. Image 3_relief.tif changed:
Diffuse :
Factor = 100
Radius = 2

6. Binarization
B&W image extraction, 3 masks

------------------ End Log ------------------

Processed image before Binarization:



Binarization.

!!! SWITCH OFF the Combine Masks option!!!

Masks were formed for:
1. The main group of tints
2. Intersections of green and brown lines
3. Light areas (this mask had been done roughly, as I realized later)

Range selection for the main mask
Always remember that overlapping of all three color intervals
causes capture of grey tints, i.e. irrelevant pixels (rubbish).



Mask for gap filling at crossings with green lines



Mask for light parts of lines



Then I clicked the Binarize button to extract a black-and-white
image corresponding to these three masks, saved it as 3_relief_BW.tif,
and added to the project.

The following sequence of operations smoothed 3_relief_BW.tif
and helped to delete rubbish:

1. Color mode transformation into 24bpp

3. Image changed:
Diffuse :
Factor = 100
Radius = 2

4. Image changed:
Unsharp Mask :
Factor = 500
Radius = 7
Threshold = 49

5. Image changed:
Contras Enhancement :
Channel: RGB
Input values 219/223
Output values 0/1.00/255

6. Color mode transformation into B&W (1bpp)

At the fourth step, the image looks like that:



The fifth step – boundary specifying between black and white.



Transformation into black-and-white again, and vectorizing.
On the whole, preparing of a B&W image consists of:



Miscalculation at mask forming for light tints is clear there.
Well, I’m too lazy to do it anew.

There may be more than 3 masks of course. But anyway, it is better
to consider the image first and to make masks for all main cases
of color overlapping than to poke it unthinkingly…

We proceed to vectorizing. Version 7.99 does not provide many
choices here. Nevertheless, it may be reasonable to play with options.
(vectorizing-> appraisal ->Undo->parameter improvement->vectorizing)



Breakup joining.

We do not recommend to sew lines across gaps just after autotracing.
Clean vector data with Editor a little first. Unfortunately, it is rather
boring operation in 7.99 – I want full-blown Vector Eraser badly...



FOR ATTENTION OF BEGINNERS!
Vectorizing technique in Easy Trace supposes
line smoothing and line form optimization
AT THE FINAL STAGE OF PROCESSING.
It means, after final manual correction
of line form and connectedness.
This example demonstrates extraction of
IMAGE lines and does not comprise
Final stages of vectorizing!
Line form optimization see in videos about 8.7

P.S. Here is the project for those who wish to train.

I have changed maximum permissible size of attachments. It is 10 MB now.

Thank you for the example of image processing startegy.

And why this image instead of the "right" one I sent later?

trace98
And what about TIFF displaying?

I used JPEG as an example because:

1. Most images (taken from web usually)
are over-compressed JPEGs of low resolution.
This is more typical situation by far than “right” files.

2. I simply had prepared the example earlier than received
the “right” image.

Everything is easier for TIFF 600 dpi 24bpp – just compare by yourself.
The technology is demonstrated in videos about 8.7.
V. 7.99 differs mainly by absence Subject Layer Extraction
and Image Thinning tools. The former may be substituted
by Binarization, but Thinning is really required.
Although, you may try to extract “line crests”:
Diffuse->Unsharp Mask->Brightness-based filtering

As for support of TIFF format – I shall clear it up.