Could be good for Commons to have some help files on the best practices of extracting illustrations (if not clipart...) from scans. So this may be of interest and maybe folks here have some advice for using Gimp etc too.

cheers, Brianna

---------- Forwarded message ---------- From: John Olsen johnny_automatic@mac.com Date: 17 Oct 2007 13:21 Subject: [Clipart] Clipart mining guide To: clipart@lists.freedesktop.org

I have had a couple of people ask me to go through the steps I use to get images from old books. I am happy to share them. I can only do a version using an Adobe Creative Suite workflow as this is what I am most familiar with and it seems the GIMP needs some additional helpers to handle PDFs. So I imagine this all can be done with an Open Source workflow. I just am not the authority to write on it. Maybe someone can translate it.

Anyway, I have a draft below. I was thinking of adding it to the Wiki section "http://openclipart.org/wiki/Clipart_Acquisition" but wondered if that clutters up that section. maybe it is better in a separate subsection under either "Clip Art Information" or "Contributor & User Handbook". If so someone who can unlock the top level would need to set that up for me. Ryan?

Any suggestions or ideas are appreciated.

John Olsen

== Guideline for Mining Images from Online Book Libraries == * Sites such as those collected under the texts section of www.Archive.org offer a gold mine of Public Domain images. This is a guide to how to extract these images for use here on OCAL. Please note the author uses a workflow using Adobe Creative Suite 3 because he is most familiar with this software. It probably can all be done using Open Source software. Someone else will need to add those instructions. * Find a book with images you would like to extract. Keep in mind that the resolution is not extremely high so small images may not have enough resolution to extract good SVGs. * Download the PDF version of the book. It usually has the best resolution. The black and white PDF will be made for reading the text and might not have the best images. it is better to get the full color PDF and do your own adjustments. * Open the PDF in Photoshop. You will be asked to select a page. Pick the page you want and open it. Then crop the image tight around the graphic you want. * Alternatively you can extract individual pages using Adobe Acrobat and then open these single pages in Photoshop. This can be faster and less memory intensive when mining large books. * Using Image>Adjustments>Black & White convert the image to black & white. The High Contrast Red Filter Preset usually does a good job. * Further enhance the image using Image>Adjustments>Brightness/Contrast to increase contrast and brightness if necessary so you get a nice high contrast image. * Save the file as .PSD or .TIF or any format that Adobe Illustrator opens. * Open this file in Adobe Illustrator. * Use Live Trace to convert photo to vector art. The following presets usually give the best result. One Color Logo (give black lines only-smallest file size), Black & White Logo (white parts are filled shapes as well) and Comic Art. * When happy with the image, Save as SVG. Do not preserve Illustrator editing so file is basic SVG. * Using File>Save for Web & Devices make a PNG file to upload with SVG. * Upload file to OCAL. * You usually get better results with strong black & white images. They make nice clean traces with reasonable file sizes. It is easier to color these afterwards then try to trace a full color image and expect clean, crisp lines. _______________________________________________ clipart mailing list clipart@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/clipart