shrink an image

[zby]

Hallo,
let's say that I have an image file of size of 1000x2000px
I use
>> set img [image create photo -format "tiff" -file "test.tif"] <<

Now I need to shrink it into a 640x480 and idsplay it like
>> pack [lable .one.l -image $img] <<

Can you give me a clue on hoe to shrink it?
PS. A newbie.
Thank you

 

[Bong]

I know I've done this but not for a while. If I recall correctly, you do that during the "image create" step. You can specify -width and -height options (in pixels).

Bob Rashkin
rrashkin@csc.com

 

[zby]

Thanks, however this:
>> set img [image create photo -file "test.tif" -width $f_one_width -height $f_one_height] <<

is what you probably mean and it doesn't satisfy me. This command doesn't shrink. It creates the xy target border of the image area to display. Once I apply this construction I see just a portion of the image within the -width $f_one_width -height $f_one_height area.

Doesn't occure to you that it could be done through:
>> $img copy .... << ?
zby

 

[Bong]

There is a -shrink option under the image copy commands but I don't think it does what you want, really:

Specifies that the size of the destination image should be reduced, if necessary, so that the region being copied into is at the bottom-right corner of the image. This option will not affect the width or height of the image if the user has specified a non-zero value for the -width or -height configuration option, respectively.

Bob Rashkin
rrashkin@csc.com

 

[zby]

Thanks for a reply.
I tested the -shrink option, but the whole application crashed for the "unauthorized access to memory" attempt. Weird, but true. I may do something wrong then.
However I tested:
>> package require img::tiff
>> ....... some code .......
>> set source [image create photo -file "test.tif"]
>> set img [image create photo]
>> $img copy $source -subsample 4 4
>> pack [label .one.l -image $img]

This construction cause to zoom out (staticly) which I want! However, to accomplish the whole project I want to be able to zoom in/outwith a button press, leaf through tiff pages if multitiff etc.
I'm using tkimg1.3rc2 package, but yet I did not find out how to process the multitiffs.
Also the:
>> $img copy $source -subsample 4 4
expression seems to me a waste of memory while another image ($source) must be opened to perform the copy. Unless I am mistaken.
I need to find out a function that initialy fits the image into the current window/frame and dynamicly changes its size according to the instant window/frame size.

 

[ulis]

Does this page:

http://mini.net/tcl/ShrinkingAnImage

meets your need?
(the coef is the same following the x and y axis, but it should be possible to enhance the proc)

ulis