Trying to figure out best settings for rendering

Support Questions for the Sketchy Software
Jfarro
Posts: 3
Joined: Wed Oct 07, 2015 2:24 am

Trying to figure out best settings for rendering

Postby Jfarro » Wed Oct 07, 2015 2:35 am

Hey gang, when I render a line art image, I usually get an image with 'dots'. I tried sending it to the quickdraw bot anyway, and sure enough it started drawing dots instead of lines. It's as if half the image doesn't get connected.

I am wondering if there are recommendations on how to fix this. One solution I've found is to lower the pen width down to .01mm, however that is narrower than my actual pen by quite a bit, and seems to wreck the drawing.

I've tried other settings and had no luck..do I need to do some pre-scaling of the image before hand? These are fairly simple images (I search for Coloring Page and then whatever I'm trying to draw typically).

If you have any suggestions please let me know. Then Pen I'm using has a bit of a thick end on it. When I use thin (0.3mm based on packaging) pens I get incredible results...but in this case I want to use a much bigger pen.

One other note..the canvas is a 50" 16:9 size...but its horizontally oriented

mhavlovick
Site Admin
Posts: 26
Joined: Fri May 01, 2015 6:51 am

Re: Trying to figure out best settings for rendering

Postby mhavlovick » Wed Oct 07, 2015 3:39 am

Can you send me the image you are using, as well as a screenshot of the rendering parameters you are using? Can you also send me screenshots of each of the setup screens?

matt@quickdrawbot.com

Thanks!

-Matt
Matt Havlovick
Owner/Maker - QuickDrawBot
http://www.quickdrawbot.com

Jfarro
Posts: 3
Joined: Wed Oct 07, 2015 2:24 am

Re: Trying to figure out best settings for rendering

Postby Jfarro » Wed Oct 07, 2015 4:25 am

Thanks a bunch, mail is sent off!

mhavlovick
Site Admin
Posts: 26
Joined: Fri May 01, 2015 6:51 am

Re: Trying to figure out best settings for rendering

Postby mhavlovick » Wed Oct 07, 2015 4:59 am

Ok, it turns out the the original image is a pretty high resolution compared to the render image it creates. I tried a few java modes to scale it differently, but they all do the same thing. I rescaled the image using at external editor using the "Area Averaging" algorithm and the image turns out much better.

Over the next couple of days, I'll see if I can update the code to use this type of scaling instead. Until then, I would recommend trying to find lower resolution images so it doesn't have to scale down so much or find a program that you can scale it down using a different scaling algorithm.

At your drawing size and pen width, the rendered image turns out to be about 159x161 pixels.

The editor I tried using can be found at: http://www.jhlabs.com/ie
Download link: http://www.jhlabs.com/ie/ImageEditor.jar

Just make sure to have Java installed and then open the ImageEditor.jar file. Open up the image and go to the "Image" -> "Image Size..." menu option

Resize it to around 160x160 with the "Area-Averaging" method and then save the image. Now try using the saved image to upload to the QuickDraw.

Oh, one other thing. With this scaling method, it seems to lighten the image, so you may have to lower the brightness and/or threshold levels when rendering.

Let me know if you have any questions.

Thanks,

Matt
Matt Havlovick
Owner/Maker - QuickDrawBot
http://www.quickdrawbot.com

Jfarro
Posts: 3
Joined: Wed Oct 07, 2015 2:24 am

Re: Trying to figure out best settings for rendering

Postby Jfarro » Wed Oct 07, 2015 5:28 am

Thankyou...that makes total sense now that you mention it. I was thinking higher res photos would give it more data to work from, but I could see it losing a lot in scaling. I also overestimated some aspects such as what resolution I could print.

For those that hit this later..I was using a canvas of 1000 x 400, with a mm pitch of 2.5 (400/2.5 = 160, thus my resolution limitation..I believe this is where Matt's getting the res from). That's good to think about when picking images.

I resized it in MSPaint and set a lower threshold and immediately got improved results on the render. I'm drawing an image up now!

Thanks for this..now that I have a better idea of resolution..and since I'm stuck with this pen size for now..I'm going to try to scale the bot up to about 2000 x 800 and see if I can get a bit more of my target images rendered