Search found 88 matches

by imaggie
2016-09-02T00:13:42-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

With respect to your fx calculation. Can't you do that ahead of time with a string format and put it into a variable and then use the variable there, if limited to IM 6. Thanks for confirming. I have installed IM 7.0.2 Where can I find the correct syntax for inserting fx into geometry arguments? Th...
by imaggie
2016-09-01T10:56:33-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

I guess without an image, I do not fully understand what you are trying to do.
I posted a link to the image yesterday, see above.
It's the Juno Earth fly-by efb12 I'm playing with. They're rather large but if you'd rather have the image ::
http://www.msss.com/junocam_efb/efbimg.html
by imaggie
2016-09-01T10:12:19-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

Thanks, I'm not sure which of us is not understanding the other here. The image is a exact multiple of the 128px strips in height. the width is fine but there is an alignment issue. ( in fact it looks like scaling more than a shift but if I can set some Affine params successfully then I can scale or...
by imaggie
2016-09-01T00:57:54-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

If your problem is getting crops that are not full size regions, seems to me that it would be better to initially crop your input image to a multiple of your crop sizes rather than trying to remove them at the end. No, it's in the other direction. I have wide, short ( y ) strips which have some ( 1...
by imaggie
2016-08-31T18:14:38-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

Thanks but it's not the strips I want to remove here, it's the lower 13 pixel rows of ALL the strips which remain after -delete "$list,$list2" just before the final append. OK this seems to do it. I could not work out why -crop didn't do it, but I was not providing the offsets. convert junocam_efb12...
by imaggie
2016-08-31T16:58:46-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

yes thanks, I've found the missing +repage. This is behaving sensibly now. I need three lists made by seq to skim out each colour plane, list1=`seq -s , 1 3 76` list2=`seq -s , 2 3 76` list3=`seq -s , 0 3 76` it works OK like this: convert junocam_efb12_roll.png -crop 1648x128 +repage -delete "$list...
by imaggie
2016-08-31T16:38:29-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

convert junocam_efb12.jpg -roll +0+3328 -crop 1648x9856 -delete "1,2,3" junocam_efb12_roll.png OK, the geometry thing is something else. I had rolled and cropped to get rid of all the dead wood and get a more managable file size. It looks OK in display or GIMP and file reports sensible dimensions e...
by imaggie
2016-08-31T16:03:12-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

Thanks, Fred. I'm hopeless at bash. The job sounds quite simple. But, rather than creating all the slices, saving them as files, then reading every third one, it may be easier and quicker to do all the processing in a single convert. If the OP puts up a source image, we may be able to advise better...
by imaggie
2016-08-31T15:58:26-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

Hmm, having trouble getting the list arg to work:

Code: Select all

convert  input.png  -crop 1648x128  +repage  -delete "$list"  -append  out_%03d.png

convert: geometry does not contain image `input.png' @ warning/transform.c/CropImage/716.
by imaggie
2016-08-31T15:21:43-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

Re: mergeing stips with offset

Thanks, I can create the list of numbers in bash and use a shell variable as suggested.

Code: Select all

list=`seq -s , 1 3 10`
echo $list
1,4,7,10

I was wondering whether fx can do that sort of thing.
by imaggie
2016-08-31T14:21:34-07:00
Forum: Users
Topic: mergeing stips with offset
Replies: 33
Views: 16319

mergeing stips with offset

Hi, I have an image which is a lot of stips one under the other. So far I have split them into separate images. convert input.jpg -crop 1648x128 +repage out_%03d.png next I recompose them using every third strip: ( it's actually the 3 RGB layers interleaved ) convert out_234.png out_237.png out_240....
by imaggie
2012-08-18T12:57:51-07:00
Forum: Digital Image Processing
Topic: proper scaling of the Jinc filter for EWA use
Replies: 234
Views: 424680

Re: proper scaling of the Jinc filter for EWA use

I do not recommend the schemes I've called LanczosSharpest, at least with 3-lobes (the most interesting case). (De)blurs below .91 or so with EWA Jinc-windowed Jinc 3-lobe lead to subtle artifacts I really dislike. This is despite that the LanczosSharpest schemes rank very high in the re-enlargemen...
by imaggie
2012-07-19T05:49:18-07:00
Forum: Digital Image Processing
Topic: proper scaling of the Jinc filter for EWA use
Replies: 234
Views: 424680

Re: proper scaling of the Jinc filter for EWA use

Just thinking on the hoof here, how does adding a small slice of a lobe compare to removing a similar amount?

Does adding a small slice soften , as I suspect, or increase the ringing due having fractionally more lobes ?
by imaggie
2012-07-19T05:41:41-07:00
Forum: Digital Image Processing
Topic: proper scaling of the Jinc filter for EWA use
Replies: 234
Views: 424680

Re: proper scaling of the Jinc filter for EWA use

(3,1) is the position of the nearest "untouched" input pixel location when the disk is centered at an input pixel location located at (0,0) and one slowly enlarges the disk from radius 3. What is 3.1 ? Presumably this is not anisotropic in x,y . Does this mean one sinc lobe equals three jinc lobes?...
by imaggie
2012-07-19T00:10:40-07:00
Forum: Digital Image Processing
Topic: proper scaling of the Jinc filter for EWA use
Replies: 234
Views: 424680

Re: proper scaling of the Jinc filter for EWA use

Code: Select all

sqrt(3^2+1^2). Probably more than a bit less.
How about sqrt(3^2) ? ;)

Sorry if I've lost the plot on this, but how does the geometric mean of 3 adn 1 give you exactly three lobes ?