Export image to dwf

[Anonymous]

Hello,

I have old scanned plan (jpg / pdf), size - 7mb , it's the smallest size and still remain readable ,
I pasted it in the layout .I made export to dwf .
The dwf file size after the export is 30mb .
it's too much big ,
How can I reduce the dwf file size at least 7mb as the source.

Thanks

[TheCADnoob]

7mb is still a very large file. I would try to reduce that file size some more if i were you. 

if you have adobe you can save your PDF as a reduced sized PDF. I regularly deal with full size (D and E) raster drawings in pdf format and they are usualy around 1mb if not less. 

Is your image black and white? you may be able to trim your file size by conveting it to black and white if it is not already. 

[john.vellek]

Hi @Anonymous,

@TheCADnoob's solution is probably a good idea. SInce the scan is raster based the DWF doesn't really give you the compression you need. A plot or export to PDF at the correct resolution will get you closer to your goal.

[Anonymous]

I need only dwf .
The real plane size is 35" X 150" ...
It's the smallest size that i could compress it .
But i noticed ,that if i use b&w image even it's 26mb 200dpi , after the
export it became 20mb ,
when i use the color image (7mb ,150dpi) ' it became 30mb ... !?

[Alfred.NESWADBA · Accepted solution]

Hi,

when you speak about "26mb 200dpi" or "7mb ,150dpi" you are speaking about the image resultion you used during scanning.

But what is the DWF setting for your output resultion? That is what the DWF makes smaller or larger.

- alfred -

[Anonymous]

I thought that the values of the image will affect the export of dwf,

basically you say what affect it - is the definition of the dwf.
I tried, it reduces from 30 MB to 20 MB.
I do not see why this could not stay closer to the original size of the image.
What information is added ?
 

[Alfred.NESWADBA]

Hi,

>> I do not see why this could not stay closer to the original size of the image.

Because of two reasons:

• the original image might be a TIFF or JPG with hard compression, the output to DWF does not compress the files in that strong way
• if the image is scanned with 150dpi, then scaled in AutoCAD by factor 2 (which now makes a data size factor of 4) and then generated as DWF with 300dpi it's again a scaling by 2 in X and 2 in Y direction ==> again a factor of 4 ... and the result of scaling twice means you have a data amount of 16 (4 * 4) for the output compared to the input. I know that this is a calculation that might differ to your real situation (which I don't know), but on the other side I only have used a small factor, it might be more.

Resume to the DWF output: it resizes the image to the output, independent from the size it had previously.

If you have an image with 100x100 pixel and you plot that to 10" x 10" by 300dpi it will be scaled to 3000x3000 pixel.

- alfred -

[Anonymous]

Hi ,

First of all thank you for the reference and investment.
I think you're really brings me to solve the problem.
My problem is :
I have scanned plan as jpg, I can't get the dwg file.
It compress to JPG, 150dpi ,5300x16000 pixels ,7mb (the smallest resolution and still readable).
I need to export it as dwf size 35"x150".
I need it to be readable .

Would you please tell me how do I calculate by your explanation for this situation?

Thanks

[Alfred.NESWADBA · Accepted solution]

Hi,

>> I need to export it as dwf size 35"x150".
>> I need it to be readable

As "readable" is a relative wording (how large are the text objects, how far do the user stay away from the poster/paper, ...) I would make it simple:

Plot to DWF with varying resolutions for raster image (look to the above screenshot) and decide by yourself which is the resolution fitting best to your needs (as readable as necessary, as small filesize as possible).

The lower the resolution the smaller the filesize, but the readability also gets reduced.

Good luck, - alfred -

[Anonymous]

Hi,

Thanks
It really helped, last night I did a lot of experiments with the resolution.
And actually managed to significantly reduce the size of the dwf.

God bless you
Thank you for your patience

Eliraz

[Alfred.NESWADBA]

Hi,

you are welcome, good to know you got it working in the way you need it 😉

- alfred -