Image editing. Need advice on how to isolate an object from the background - for big batch of images.

March 3, 2010 9:05 PM

Image editing. Need advice on how to isolate an object from the background, and apply a consistent white background for a batch of product shots.

I've been asked to photograph a household inventory. Furniture, clothing, vases -- all in a cluttered space. Client wants the images edited to remove the clutter around the sofa, vase, etc. Needs a consistent white background on all the images. Client wants the images to look like this web site.

When I take the photos, I plan to bring white sheets and a neutral grey board to place behind some of the the objects But I will still need to select out the object and make consistent white backgrounds.
Is there an efficient way I can edit the images myself? Other than painstakingly clicking a selection path?
OR
Do you have experience with a reliable service company that can edit the whole batch of images?

My software: Photoshop Elements, gimp, picasa.

posted by valannc to technology (10 answers total)

For what it's worth, this should actually be pretty easy in the GIMP (although I don't know exactly what you mean by "painstakingly clicking a selection path.") Don't use the lasso or basic selection tools - use the intelligent selection tool, which is the little scissors icon. (The keyboard shortcut is "i.")

Just select the intelligent selection tool and click somewhere close to the edge of the object; a dot will appear, signifying your beginning point. Moving along the object, click on the edge every so often; the tool will intelligently select the edge based on color difference. When you get all the way around the object, click your starting-point once, and then move your cursor inside the selection area; a tiny eclipsed-circle emblem (sort of like a venn diagram) will appear above the pointer. Click inside the selection area, and the lines you've drawn will turn into a selected area. Press control-i to invert the area to the space around the object, and then press delete.

Go back over the edge and select the chunky or rough edges. This shouldn't be too time-consuming; I've found the intelligent select tool is pretty efficient. You might also get some mileage out of the fuzzy select, the color select (shift-o) and (if an object is very curved) the paths tool, although that last is probably something you won't need.
posted by koeselitz at 9:22 PM on March 3, 2010 [1 favorite]

Your first and most important step is to make sure the white sheets are well-lit. If you have them draped behind the furniture, see if there's any way you can get some light directed *at them* in addition to the furniture or object itself. That will help cut down on deep shadows falling on the white backdrop. As long as you have good contrast at the edges of the furniture, rather than a fade into the shadows, tools like the 'intelligent selection' in GIMP and the 'magic wand' in photoshop can get you 90% there. The rest is, yeah, annoying manual touch-up, but ensuring that your original photos are cleanly lit makes a WORLD of difference.
posted by verb at 9:26 PM on March 3, 2010 [1 favorite]

By the way, if you were looking for a way to automate that process and batch-edit images, it would be a little tougher but certainly possible with ImageMagick.
posted by koeselitz at 9:26 PM on March 3, 2010

Photoshop instructor here...

How big is the batch? If it's 20 images or so, do it in GIMP with the lasso tool in polygonal-select mode (point and click around the object like you're connecting the dots) then make sure your background color is set to white, ctrl+i for invert selection (last I checked) and press delete. Save, move to next image.

You can zoom and pan while using the lasso tool in GIMP too, just ctrl+mousewheel to zoom, and hold down middle mouse button and move mouse around to pan. If you need to delete a few points that you made on accident, the backspace key will jump you backwards.

99% of the selection stuff people do is done faster and simpler this way.

Is the client pretty image un-savvy? If so, and if they haven't given you specs on what pixel dimensions they want the final web-res image to be, make your white-background edits in original-size mode THEN resize to the web-res image using a dimension like 640x480 (good enough for the web in most cases). This will make sloppy work on your part less obvious. Not that there should be much anyway when you get the hang of it.

Now if the batch is like 500 images, go find somebody else to do it...
posted by circular at 10:34 PM on March 3, 2010

If the batch is 500 images, it'll be easier to just hire a professional who owns good lights and a backdrop and get the photos right the first time instead of wasting hours photoshopping.
posted by beerbajay at 1:57 AM on March 4, 2010

Why not set up a decent sized softbox and avoid selective editing altogether? Just ensure that the sheets/paper/whatever of your softbox are lit bright enough to expose to pure white. It will be much faster to bring the objects to the softbox than shoot them in situ and edit the crap out of them.

PM me if you still need more help.
posted by hamandcheese at 6:57 AM on March 4, 2010

If you have a white background around your objects, and the objects themselves contrast against it, then I would use threshold.

Threshold, in Photoshop, is found under the Image menu, I believe. What it does is to make every pixel over a certain brightness white and every pixel under a certain brightness black. Basically, since you'll have the sheet as one brightness, and the object as stuff that's going to be darker, you'll get a black and white outline of your object.

The way that you make this work is you first make a duplicate layer, apply threshold, magic wand select the black outline on the threshold layer, go to the layer with the actual image, and copy it. There you go. An isolated selection of the object that you can paste onto a matte white background.

I hope that explanation makes sense. Without Photoshop in front of me I might not be getting the right terminology.
posted by codacorolla at 8:03 AM on March 4, 2010

I've had remarkable results placing small to medium sized items on a sheet of plexigas, raised above with the white backdrop by enough space so that I can illuminate the backdrop completely around the product with no shadows. This process made use of the magic wand tool in Photoshop work with one click like 98% of the time. For larger items such as the sofa, I suggest simply raising it on something like bricks or books so your surrounding light can get underneath and around it, which will contribute greatly to making selections. Another idea is to suspend the items from a long hook that projects from the wall, which is obscured by the item you are image capturing (with the backdrop behind it).
Also, remember to feather the edge of your selection for best results... Select > Refine Edge > adjust sliders in PS.
posted by Oireachtac at 9:54 AM on March 4, 2010

Many thanks for all these great responses. For this particular job, I used the GIMP technique as described by Koeslitz. But I'm saving all the advice and tips above.
posted by valannc at 8:07 AM on March 5, 2010

The google search phrase you were looking for is clipping path service.

Tons of providers, prices range from $0.50/image on up depending on volume and complexity.
posted by joshwa at 2:46 PM on March 17, 2010