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View Full Version : Which raster to vector software is best?



slawman64
01-06-2007, 07:55 AM
I just received my compucarve, I want to carve jpegs(people, dogs) and I can't seem to get good results. What kind of photo manipulation software is best for converting to vector images that can be used in the designer? Thanks

BobHill
01-06-2007, 09:18 AM
That's the tricky one Slawman. There is no immediate transfer from any raster image to the proper carving image in Designer except for some pretty expensive software (ArtCam for example). You certainly can experiment with using gradients and put your image into 8bit shades of gray mode though. PhotoShop is the raster program I use personally. remember that a JPEG is a lossy format, so I'd not use that when doing the work. Use something like PSD, or TIFF and only make it into a JPEG (or better yet a BMP) after you've completed your work on it.

Bob Hill
Tampa Florida

Jeff_Birt
01-06-2007, 09:37 AM
When you import JPG/BMP/PNG into Designer it uses the grey level to set the depth, black being the lowest and white being the highest part of the carving. Photographs have no depth information to them thus you don't get good results. I've been playing with Blender - (It's free)


http://www.blender.org/cms/Home.2.0.html]
http://mediawiki.blender.org/index.php/Tutorials/Creating_a_Heightmap_from_a_Plane
http://mediawiki.blender.org/index.php/BSoD/Introduction_to_Modeling/Our_Own_Genesis

hoping that I can figure out how to make nice 3D images for my CarveWright.

Also, as I understand it PNG is a lossless compression teqnique and wonder if it might be better for transferring things to the CW.

BobHill
01-06-2007, 10:02 AM
Jeff,

Actually PNG format was adapted and accepted by the WWWC for use on the WEB as a format which would carry vector information as well as it was created in a vector program but it's in a raster format. It also is NOT a lossy format as the standard JPEG is, and yet is highly compressable as is the JPEG. It never has become very popular. There is a new JPEG format (also not recognized by many software programs), which is JPEG 2000 that is also highly compressible without being LOSSY in color quality as the standard JPEG is.

I've tried using PNG in Designer and it failed miserably, so I avoid it like the plague. BMP might be the better format, but then it's going to take up more storage space than a JPEG too. Since the CW only using 8bit shades of gray, using anything with RGB is a waste, so perhaps if one uses the 8bit GIF in shades of gray, that would work. However, one would need to do the conversion within PhotoShop (or?) or I'm afraid the CW wouldn't use the right method of converting 8bit color to shades of gray. I doubt that the CW allows other than standard 8bit color (paint by numbers type of color) rather than the more powerful 8bit indexed color ability high end raster formats allow.

Bob Hill
Tampa Florida

Zclip
01-06-2007, 11:38 AM
Just to mention here, JPG can also be 'Lossless' but you trade off better image quality for larger (sometimes megalithic) file size. When you save off a JPG, (in Photoshop and CorelDraw) you get prompted with compression and smoothing options. if you save the file off with no compression and no smoothing, you get a "pure & unadultrated" image.

Photoshop is pretty much still the benchmark for Raster programs, and has been for well over a decade. Corel also makes a program (usually bundeled with CorelDraw) called Photopaint (I think) and there are some other programs that are cheaper & afford a lot of functionality such as Paint Shop Pro.

Hope this is helpful

BobHill
01-06-2007, 11:47 AM
Z, unless you are talking about JPEG 2000, I'm afraid that's not true. A JPG is ALWAYS progressively lossy (color quality) each time it's opened and Saved, including the inital conversion from vector to raster. That's the nature of it's algorythm. Having said that, however, since RGB isn't a factor for Designer, as it only uses 8bit shades of grey, I'm not so sure using PhotoShop changing mode to 8bit shades of grey and then Saving that to a GIF format might not be best as it's bound to being an 8bit format, color or shades of grey.

Bob

Zclip
01-07-2007, 03:01 AM
Z, unless you are talking about JPEG 2000, I'm afraid that's not true. A JPG is ALWAYS progressively lossy (color quality) each time it's opened and Saved, including the inital conversion from vector to raster. That's the nature of it's algorythm.
Well, I'm not going to out & out refute that, however, it is to my experience & understanding that if you create a JPG with either PS or CD, and don't compress or smooth it, then every pixel will retain it's discrete RGB value, thus, no loss. now you go me interested in a test of this info,,, tomorrow sometime, after I sleep.



Having said that, however, since RGB isn't a factor for Designer, as it only uses 8bit shades of grey, I'm not so sure using PhotoShop changing mode to 8bit shades of grey and then Saving that to a GIF format might not be best as it's bound to being an 8bit format, color or shades of grey.

Bob

Duh! You're quite right, curse me for a smack-tard. ;) I purdy much forget about GIF until I need to animate. In my mind JPG has just become synonymous with 'Raster Image' no matter what the color depth.

BobHill
01-07-2007, 09:53 AM
Z,

I used to teach PhotoShop, Illustrator, CorelDraw and did some work for Adobe for a few years, but the only reason for bringing up JPEG's compression algorythm is because of how it might translate it's lossiness when converted to 8bit mode shades of gray when certain pixels have been given another color than the original when exploded after compression. GIF uses LZW type of compression and that is NOT lossy. With the number of times a JPEG is opened and worked on, then saved (and each time it loses more color quality, but even the first save to a JPEG is lossy) might well effect the shades tone, thus it's cutting depth at those points. I'm wondering if it's also why some raster carving cuts using JPEG isn't why you see so many "drill" holes in the piece.

Bob

Zclip
01-07-2007, 11:01 AM
Ya know, Bob, I think I'm just going to defer to your wisdom & experience on this. It will at least save me some research time, though now I have to go back to several PDFs and compare them with the JPG proofs to see how much degradation has occoured,,, ugh! Stoopid lil' 1's & 0's!!! ;)

BobHill
01-07-2007, 11:25 AM
I'm not sure how many are interested in this thread, Z, but an easy experiment to see the effect of JPEG's lossy compression technique is to take an original PSD/TIFF image and save it to a standard JPEG. If you open both side by side (I use two 19" SONY flat monitors which makes this very easy) it'll be almost impossible to see the difference, which makes it's first compression (save) to have no loss (but it truely is there). However, take that same JPEG and now open it and Save it as a JPEG ten times without doing anything except opening and Saving (not just closing) it. After ten Saves, Open this tenth version of the JPEG and compare it in zoom with the original PST/TIFF. You'll have no trouble seeing the differences, bit time.

Bob

BobHill
01-07-2007, 01:09 PM
Without getting too technical and boring, a LOSSY color format (raster or photo image) is one that using a mathematical algorythm which removes a number of pixels (the more you compress, the more pixels are removed) from the image then then compresses the zeros and ones into a far smaller file for storage. Because this image will have far less pixels than one that just uses a mathematical formula without the pixel removal, the file will be far smaller than other compressed formats and greatly smaller than a file without any compression (such as a BMP or TIFF without a compression option). Now when any compressed image is "Opened" in a program that'll recognize it, the zeros and ones once again will reappear with just as many pixels as the original, BUT when the compression is lossy and pixels were removed, although those number of pixels are once again present, the color attached to those missing pixels is NOT there. Thus the format (JPEG) has to assign a color to those missing pixels and does so in one of two methods: 1) averaging laterally the colors of the two (or more) pixels the now blank pixels fall between or 2) bilaterally averaging the pixels the blanks now fall between. When a lossy format image is again saved, it DOES NOT pick the same pixels to remove, thus when it's exploded again, it goes through the color averaging again, only now more pixels are using the average and those colors seldom are the same as the very original image was.

JPEGs are the most popular images because you not only can choose the amount of compression (make the storage file smaller), but it's a full 24bit (RGB) color and the WEB will accept that format as will most other programs. But because of this popularity, many people either forget or don't know about it's LOSSY attributes.

Hope this isn't too boring for those without the interest.

Bob