Re: [Gimp-user] what is dpi, ppi and lpi
On Fri, 12 Apr 2002, Amit Mukherjee wrote: Hi, Can anyone tell me the difference between dpi, ppi and lpi ? If my intention is to print a picture measuring 8x10, at what resolution should I scan ? dpi = dots per inch ppi = pixels per inch lpi = lines per inch to know the minimum you need to scan you'll need to know what sort of dpi your printer is capable of printing. Lets say its an ink-jet that'll handle 1000dpi To print an 8x10 without having to scale the image up or down to make it fit you'll need to scan... 8000 x 10,000 pixels! Pretty easy eh? Depending on the software you're printing with you might be able to get a decent print from less. If you're going to be retouching the scan you might want to scan at double or triple the resolution of your printer so you can make really fine corrections and then scale the image down to the maximum size your printer can handle right before you print. Enjoy! -- Jon Winters O O O O O O O History Will Prove us right O B S C U R A http://www.obscurasite.com/jon/ / \ / \ / \ / \ / \ / \ / \ ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] what is dpi, ppi and lpi
Jon == Jon Winters [EMAIL PROTECTED] writes: Jon On Fri, 12 Apr 2002, Amit Mukherjee wrote: Hi, Can anyone tell me the difference between dpi, ppi and lpi ? If my intention is to print a picture measuring 8x10, at what resolution should I scan ? Jon dpi = dots per inch Jon ppi = pixels per inch Jon lpi = lines per inch DPI is normally used for scanners, printers, and monitors. LPI is normally used for half-tone screened images. A 100 LPI half-tone image corresponds to a much higher DPI rating. Jon to know the minimum you need to scan you'll need to know what Jon sort of dpi your printer is capable of printing. Jon Lets say its an ink-jet that'll handle 1000dpi To print an Jon 8x10 without having to scale the image up or down to make it Jon fit you'll need to scan... Jon 8000 x 10,000 pixels! Jon Pretty easy eh? For most practical purposes, 300dpi for a color print is more than good enough. Scaling the image to fill whatever resolution you need for your printer should cause no problems. If you have a 300dpi image (at print scale), and produce a fiery from it, you will be completely happy with the results. For photographs, I typically scan the 35mm negatives at 2400dpi and print up to 8x12 with no perceptible loss. roland -- PGP Key ID: 66 BC 3B CD Roland B. Roberts, PhD RL Enterprises [EMAIL PROTECTED] 76-15 113th Street, Apt 3B [EMAIL PROTECTED] Forest Hills, NY 11375 ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
RE: [Gimp-user] what is optical resolution
Roland, You certainly have answered most of the questions I had in mind. I do have one remaining question, however. The digital cameras I've seen at stores like CompUSA only list in their spec. total pixels. For example 1.3 Meg pixels. My question is how can I translate this number to the print size I want to print (w/o perceptible distortion)? I print all photos on 8.5 x 11 photo paper and would like to print also at 17 x 22. I don't currently have a digital camera. I use the new Kodak format and for the developing process I request digitized photos. I don't now recall the size of each photo-file return (via CD) but I think each photo-file is a jpeg file under 1 Meg. So my real question is should I buy a $200 HP camera at 1.3 Meg pixels or a $ 200 HP scanner? jjc -Original Message- From: Roland Roberts [mailto:[EMAIL PROTECTED]] Sent: Friday, April 12, 2002 11:49 AM To: [EMAIL PROTECTED] Subject: Re: [Gimp-user] what is optical resolution Amit == Amit Mukherjee [EMAIL PROTECTED] writes: Amit Can anyone explain to me what optical resolution means. I am Amit looking at the product specification of an Epson scanner and Amit it says that the optical resolution is 1600x3200 dpi. What Amit does this mean ? Optical resolution is the real resolution of the scanner. Anything higher is interpolated and you can do at least as well in the GIMP as the scanner will do. Generally, I don't count on anything higher than the lower number; i.e., for your case, I treat 1600x3200dpi as 1600dpi. And to avoid the whole problem with asymmetric resolution, I just bought an Epson Perfection 2450 Photo scanner with 2400dpi optical resolution. We used to have an (old) Scanmaker E3 with 300x600dpi optical resolution, but I found trying to operate it at 300x600 instead of 300x300 just caused little jaggies in the results; I don't think the stepper motors were doing a good job position the platform. Newer scanners should do better, but I still prefer the scanners with resolution the same in both directions. roland -- PGP Key ID: 66 BC 3B CD Roland B. Roberts, PhD RL Enterprises [EMAIL PROTECTED] 76-15 113th Street, Apt 3B [EMAIL PROTECTED] Forest Hills, NY 11375 ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Re: what is optical resolution
[EMAIL PROTECTED] (2002-04-12 at 0549.14 +): Can anyone explain to me what optical resolution means. I am looking at the product specification of an Epson scanner and it says that the optical resolution is 1600x3200 dpi. What does this mean ? It means the scanner can see that many real dots, it can sample that info from the documents directly. In digital cameras the concept is similar, the good thing is optical zoom, not digital zoom, cos it performs the operation directly, not as post process or similar tricks. Internally the hardware have some elements, not necessarily matching the pixels you will get, but arranged and designed in such a way that the maximum optimum number of pixels is what optical resolution says. The software that comes with the scanner I have gives me a choice to scan upto 9600 dpi. How do I know whether this value is the optical resolution or the software interpolated resolution ? If it is above optical specs, it is interpolated. I can think a case in which app wants to give mid resolution at high speed, and scans at low resolution and then fakes... which is a nasty trick. This trick should not happen when using maximum quality settings with less or equal resolution than declared optical. In some scanners interpolated is (a bit) better than scaling the image afterwards, cos the driver has access to the full range of info (some scan in 30 bits vs 24 of images, for example) as well as knowing how it is made the hardware and thus can guess better. But you should always pay attention to optical, it is the real limit, other things are tricks. GSR ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Re: what is dpi, ppi and lpi
[EMAIL PROTECTED] (2002-04-12 at 0919.27 -0500): Can anyone tell me the difference between dpi, ppi and lpi ? If my intention is to print a picture measuring 8x10, at what resolution should I scan ? dpi = dots per inch This causes confusion, some file formats say DPI, and monitors too... but IMHO they should say PPI. Dots per inch, but what kind of dots? Multilevel ones like pixels? Single level like ink jets? Single level but mix capable like dye based printers (so multilevel)? ppi = pixels per inch What monitors and files have. lpi = lines per inch Or how many different lines of a set of shades you can have per inch with a halftoning printer (newspapers, laser printers, normal ink jets). The more shades (bw, 16 grays...) you want the less lines you can paint (the less fine the detail is), but more intensity levels avaliable (always supposing same printer). to know the minimum you need to scan you'll need to know what sort of dpi your printer is capable of printing. ... 8000 x 10,000 pixels! Umm, eek! The guys I know work at 300-400 DPI and A4 (210 * 297 mm) output, that gives around 3300 * 4700 pixels, less than 8000 * 1. And they do not use home printers, but professional machines with good inks and papers. For home ones I guess 200-300 is more than enough, and that means 2400 * 3300 for a full 8*10, so check what size the original is, and scan so you get that many pixels. Pretty easy eh? It is not. You will always find problems, due inexperience, not fixed definitions or whatever. Some references are http://www.aim-dtp.net/ and http://desktoppub.about.com/library/weekly/aa101800a.htm, in this last one they already say that terms are mixed, and they add SPI (samples, about scanners, normally called DPI or PPI, being PPI the most near, cos a pixel is sample, IMO). OK, I think I made it even more confusing now. :] GSR ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Re: what is optical resolution
[EMAIL PROTECTED] (2002-04-12 at 1217.06 -0400): I don't currently have a digital camera. I use the new Kodak format and for What Kodak format? Are you talking about typical relfex camera with 35mm film or another thing? the developing process I request digitized photos. I don't now recall the size of each photo-file return (via CD) but I think each photo-file is a jpeg file under 1 Meg. And in pixels? That is what really counts... and well, they could give you too something better than JPEG too (aka something lossless). So my real question is should I buy a $200 HP camera at 1.3 Meg pixels or a $ 200 HP scanner? If you can afford the development costs (both negative and a mid/small size paper copy), the scanner. Also film has better range. GSR ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] what is optical resolution
jjc == Cruz, John J [EMAIL PROTECTED] writes: jjc Roland, You certainly have answered most of the questions I jjc had in mind. I do have one remaining question, however. The jjc digital cameras I've seen at stores like CompUSA only list in jjc their spec. total pixels. For example 1.3 Meg pixels. My jjc question is how can I translate this number to the print size jjc I want to print (w/o perceptible distortion)? I print all jjc photos on 8.5 x 11 photo paper and would like to print also jjc at 17 x 22. The more common formats in digital camera are a 4:3 ratio, at least for the smaller formats. I have a 1.3 megapixel camera and it's formats are 320x240, 640x480, and 1280x960. Higher end cameras may do other things. Do a little more digging, you should be able to find something about the actual formats supported for your camera. jjc I don't currently have a digital camera. I use the new Kodak jjc format and for the developing process I request digitized jjc photos. I don't now recall the size of each photo-file jjc return (via CD) but I think each photo-file is a jpeg file jjc under 1 Meg. jjc So my real question is should I buy a $200 HP camera at 1.3 jjc Meg pixels or a $ 200 HP scanner? What's the resolution of the scanner? A 1.3 megapixel camera will never produce satisfactory prints at 17x22 and, even though Ofoto (http://www.ofoto.com) claims it will print at 8x10, the quality if marginal. Acceptable for a family vacation photo, maybe, but not for critical work. Mind you, we bought a Fuji FinePix 1400 1.3 megapixel camera last year for vacation pictures where we expect to (1) put them on the web for our family members to view and (2) occasionally make 4x6 snapshot-sized prints for friends/relatives. For 8x10 prints, I wouldn't recommend anything less than a 2 megapixel camera, but again, that is primarily for non-critical work. I'd say spend the money on the printer if you are doing artwork. Even an inexpensive color printer is acceptable for proofs. My dad does commercial work and he considers his Tektronix Phaser (don't remember which model) only acceptable for proofs. For high quality, it goes to a service bureau. roland -- PGP Key ID: 66 BC 3B CD Roland B. Roberts, PhD RL Enterprises [EMAIL PROTECTED] 76-15 113th Street, Apt 3B [EMAIL PROTECTED] Forest Hills, NY 11375 ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Re: what is optical resolution
Guillermo == Guillermo S Romero / Familia Romero [EMAIL PROTECTED] writes: Guillermo In some scanners interpolated is (a bit) better than Guillermo scaling the image afterwards, cos the driver has access Guillermo to the full range of info (some scan in 30 bits vs 24 Guillermo of images, for example) as well as knowing how it is Guillermo made the hardware and thus can guess better. But you Guillermo should always pay attention to optical, it is the real Guillermo limit, other things are tricks. Actually, this is a good point which I forgot. I've been using software other than the GIMP for initial processing (mostly level adjustment) to access the full 16-bits/color from my scanner, then doing touch-up in the GIMP. Having access to all 16-bits/color would be a great thing to have in the GIMP roland -- PGP Key ID: 66 BC 3B CD Roland B. Roberts, PhD RL Enterprises [EMAIL PROTECTED] 76-15 113th Street, Apt 3B [EMAIL PROTECTED] Forest Hills, NY 11375 ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
RE: [Gimp-user] what is optical resolution
Roland, Thank your for the information. jjc -Original Message- From: Roland Roberts [mailto:[EMAIL PROTECTED]] Sent: Friday, April 12, 2002 2:11 PM To: [EMAIL PROTECTED] Subject: Re: [Gimp-user] what is optical resolution jjc == Cruz, John J [EMAIL PROTECTED] writes: jjc Roland, You certainly have answered most of the questions I jjc had in mind. I do have one remaining question, however. The jjc digital cameras I've seen at stores like CompUSA only list in jjc their spec. total pixels. For example 1.3 Meg pixels. My jjc question is how can I translate this number to the print size jjc I want to print (w/o perceptible distortion)? I print all jjc photos on 8.5 x 11 photo paper and would like to print also jjc at 17 x 22. The more common formats in digital camera are a 4:3 ratio, at least for the smaller formats. I have a 1.3 megapixel camera and it's formats are 320x240, 640x480, and 1280x960. Higher end cameras may do other things. Do a little more digging, you should be able to find something about the actual formats supported for your camera. jjc I don't currently have a digital camera. I use the new Kodak jjc format and for the developing process I request digitized jjc photos. I don't now recall the size of each photo-file jjc return (via CD) but I think each photo-file is a jpeg file jjc under 1 Meg. jjc So my real question is should I buy a $200 HP camera at 1.3 jjc Meg pixels or a $ 200 HP scanner? What's the resolution of the scanner? A 1.3 megapixel camera will never produce satisfactory prints at 17x22 and, even though Ofoto (http://www.ofoto.com) claims it will print at 8x10, the quality if marginal. Acceptable for a family vacation photo, maybe, but not for critical work. Mind you, we bought a Fuji FinePix 1400 1.3 megapixel camera last year for vacation pictures where we expect to (1) put them on the web for our family members to view and (2) occasionally make 4x6 snapshot-sized prints for friends/relatives. For 8x10 prints, I wouldn't recommend anything less than a 2 megapixel camera, but again, that is primarily for non-critical work. I'd say spend the money on the printer if you are doing artwork. Even an inexpensive color printer is acceptable for proofs. My dad does commercial work and he considers his Tektronix Phaser (don't remember which model) only acceptable for proofs. For high quality, it goes to a service bureau. roland -- PGP Key ID: 66 BC 3B CD Roland B. Roberts, PhD RL Enterprises [EMAIL PROTECTED] 76-15 113th Street, Apt 3B [EMAIL PROTECTED] Forest Hills, NY 11375 ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
RE: [Gimp-user] what is optical resolution
Thank you for your info. John J. Cruz M$ = Fear, Uncertainty and Doubt (FUD) Linux = Wisdom, Integrity and Truth (WIT) WIT shall prevail over FUD! -Original Message- From: Roland Roberts [ mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] ] Sent: Friday, April 12, 2002 2:18 PM To: [EMAIL PROTECTED] Subject: Re: [Gimp-user] what is optical resolution jjc == Cruz, John J [EMAIL PROTECTED] writes: jjc So my real question is should I buy a $200 HP camera at 1.3 jjc Meg pixels or a $ 200 HP scanner? I just reread this and realized you asked about a _scanner_ not a printer. Sorry, I've been thinking of buying a color printer, so my brain was on the wrong track. I'd buy the scanner. If you can double you budget, I'd still buy the scanner. My Epson Perfection 2450 Photo scanner cost me about $360 and scans a 35mm slide at better than 6-megapixels. I use it for my hobby (astrophotography) where I can rarely trust the lab to print an acceptable result. In general, paper doesn't have the same dynamic range as film, so scanning from prints doesn't get you the same results as scanning from film. Still, scanning a 4x6 print at 1600dpi (the figure you originally mentioned) should allow you to print at 17x22 and still have 300dpi. You may have to do some work to sharpen up the scan, but it might work. Not having gone past an 8x10, I'm not the right person to ask for how _well_ it will work. The bigger problem is that the GIMP will only handle 8-bits/color which means you can't take full advantage of your scanner. From the rumors I've heard, this will change in GIMP 2, but I've also heard not to expect to see that for another year. roland -- PGP Key ID: 66 BC 3B CD Roland B. Roberts, PhD RL Enterprises [EMAIL PROTECTED] 76-15 113th Street, Apt 3B [EMAIL PROTECTED] Forest Hills, NY 11375 ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Virus Alert
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[Gimp-user] ps to pdf
Dear List, I am trying to create a pdf document for print using the gimp. I have saved my image as a ps file and tried to convert it with ps2pdf. The problem is that it looks really really bad. The fonts are almost unreadable and the images are grainey. How would I convert a ps file to a high quality pdf file. I have read the online docs for ps2pdf and found them a bit over my head. Any help that you could give me would help. p.s If this is the wrong place for this could someone send me in the right direction. Thanks, Will ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Welcome to my hometown
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Re: [Gimp-user] ps to pdf
Em Sexta 12 Abril 2002 19:40, the matrix traced a message in which Will Muir wrote: Dear List, I am trying to create a pdf document for print using the gimp. I have saved my image as a ps file and tried to convert it with ps2pdf. The problem is that it looks really really bad. The fonts are almost unreadable and the images are grainey. How would I convert a ps file to a high quality pdf file. I have read the online docs for ps2pdf and found them a bit over my head. Any help that you could give me would help. p.s If this is the wrong place for this could someone send me in the right direction. the easiest way out : simply open you document with you editor and hit the print button. then choose the option - print to output file. give it a name, ie, file.ps or file.pdf an easy way out : install enscrypt. another way: install latex and its gui called lyx. you can turn xdvi files into .pdf and txt and .ps files. all this of course assuming you're running linux. best regards -- * * * * * * * * * * cyberhades LINUX user number: 217052 icq number: 132859539 línguas: Português/English/Esperanto homepage: www.cyberhades.hpg.com.br more in one page of finnegans wake [deepstudied] than in the whole of life [skipped over] * * * * * * * * * * * * * * * ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Removing Background Tutorial
Since removing a background seems to becoming an FAQ, I whipped up a tutorial last night: http://www.gimp.org/~sjburges/color_to_alpha/color2alpha.html Happy GIMPing, Seth Burgess [EMAIL PROTECTED] __ Do You Yahoo!? Yahoo! Tax Center - online filing with TurboTax http://taxes.yahoo.com/ ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Removing Background Tutorial
On Fri, 2002-04-12 at 21:12, Seth Burgess wrote: Since removing a background seems to becoming an FAQ, I whipped up a tutorial last night: http://www.gimp.org/~sjburges/color_to_alpha/color2alpha.html Happy GIMPing, Outstanding tutorial. I had no idea that you could drag a color like that. HUGE tip for me. Bret ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
