On approximately 9/11/2009 12:27 AM, came the following characters from the keyboard of Anthony Thyssen: > On Fri, 11 Sep 2009 00:11:38 -0700 > Glenn Linderman <[email protected]> wrote: > > Actually as it is outside the parentesis it is applied to BOTH > setting the virtual canvas size only, while leaving the virtual offset > as previously set by the other -page options. > > "All images in the current image sequence" would be the right phrase. > Parenthesis creates a new seperate image sequence. >
Thanks for these clarifications. > Actually to save reading the image twice you can do this... > > convert.exe in.jpg -repage 1159x1515+0+0 \ > \( +clone -repage +409+765 \) \ > -repage 1159x1515 -background white -compose multiply -flatten \ > -compress zip -density 150 out.tif > > As the image data in the clone of in.jpg is not modified, only its > virtual canvas position, the pixel memory will be shared by both images! > that is this would be a near instant copy with reduced memory usage! > Would be nice, but in general, I don't have the same image twice on a page. This was just a test case, to isolate the problem I was having. I doubt I'll even check for such an optimization, it would be so rare. > | Well, I've been playing a bit with -size, since that seems to be the > | option that I had in the original command that produces the erroneous > | effect in current versions of ImageMagick, but didn't in earlier versions. > | > | It appears that with some of the techniques you have proposed, the -size > | setting isn't needed. But it appears that if it is used, it has a > | strange effect. > > HOLD!!!! yes I know what is could on. > Yippee! An explanation of my problem! But it doesn't explain why it didn't used to happen on older versions :( > The -size setting is used for creation of NEW images. (such as xc: and > gradient:) however it is also used as a 'size' hint to the JPEG library > for use when reading in images. > > Typically it is used to avoid reading in too much data. That is a large > digital photo when you plan to generate a small thumbnail. I did not know > that it can also increase the size of an input JPEG image!!! > Maybe double is the max increase. The other "steps" were all integral reductions 1, ½, ⅓, ¼, 1/5, 1/6, etc. of the original size... so this explanation is quite likely. > I think that perhaps it is time that the JPEG image size hint > be delegated to a specific JPEG codec -define setting. The use of -size > with JPEG images seems to cause no end of problems! > Well, it wouldn't be so bad if there were a way to turn it off. +size ??? But I couldn't find a way to turn it off. If there was a way to turn it off, then that could be done after canvas creation, before reading .jpg, when needed in that order. _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
