Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: bongobongo on June 09, 2006, 04:30:45 pm

Title: Need advice, how do I correct vertical and horizon
Post by: bongobongo on June 09, 2006, 04:30:45 pm

Hi.

I have scanned 40 images of framed paintings today.

Most of them was not held in plane with the film and therefore most of them
have both vertical and horizontal lines wrong.

Is there a software tool out there that manage to correct both vertical and horizontal lines in one operation.

Ideally I would like to mark the edge of the whole frame in the image (the frame here is the actual frame that comes with the oil-painting).

Then the software should adjust top and bottom horizontally and left and right vertical and of course do as good job as possible with stuff that is in between the marked lines as well :-)

NOTE: I need software where I can mark all four sides and where the software do the rest.. or something similar.

Title: Need advice, how do I correct vertical and horizon
Post by: Schewe on June 09, 2006, 06:54:37 pm

Perspective Correction in Photoshop...

Title: Need advice, how do I correct vertical and horizon
Post by: boku on June 09, 2006, 07:18:07 pm

After all is said and done, you may find that you really don't have straight lines. even when corrected for perspective. In that case, a lens distortion correction tool like the one built into PS CS or the exceptional PTLens plugin should be applied before Pespective correction.

Don't work on the original scan file! Make a copy.

Title: Need advice, how do I correct vertical and horizon
Post by: bongobongo on June 10, 2006, 05:20:37 am

Thanks for the feedback.

I searched internet for "photoshop perspective control" and found this link:

http://www.lonestardigital.com/perspective_correction.htm (http://www.lonestardigital.com/perspective_correction.htm)

which explains how to correct perspective using the Skew tool.

That was exactly what I needed since this makes it possible for me to finetune each side of the image by just dragging with the mousepointer... great tool

great feedback....

Untill next ... best regards

Title: Need advice, how do I correct vertical and horizon
Post by: Tim Gray on June 10, 2006, 09:15:20 am

Distort works in a similar way.  Distort/Skew are more flexible for your purposes than Perspective Control.

Another tip is to use guidelines.  Make sure the rulers are visible and activate the Move icon then click drag the mouse from the ruler and a vertical or horizontal line can be dragged onto the frame as a reference.  When you're done, using the move tool, place the cursor over the line and click drag it off the screen.

Title: Need advice, how do I correct vertical and horizon
Post by: plugsnpixels on June 15, 2006, 10:05:30 pm

When I fix up pix I shoot for ebay (usually at an angle to avoid flash reflection), I routinely use Photoshop's Perspective or sometimes Distort functions. For more complicated distortion (such as that introduced by the optics of the lens, I use Image Align (http://www.plugsnpixels.com/imagealign.html). I've got other distortion fixing plug-ins listed here (http://www.plugsnpixels.com/imageenhancement.html).

Title: Need advice, how do I correct vertical and horizon
Post by: ddolde on June 15, 2006, 11:54:47 pm

I'd straighten the horizonal lines first assuming they are parallel.  Then use the perspective crop tool for the verticals.  If that won't do it then you need a more specialized tool like mentioned above.

Title: Need advice, how do I correct vertical and horizon
Post by: Gordon Buck on June 16, 2006, 11:42:28 am

If you're going to be cropping anyway, the crop selection area can be rotated.  Just move the cursor close to one of the corners and a rotation arrow will be shown.  Click and drag the corner.