Re: [Gimp-user] pixels to dpi
On Tue, Apr 07, 2009 at 02:21:26PM +0100, norman wrote: Are you testing us here? You have given the dots per inch, dpi, resolution of the scanner and were just told that dots/pixels per inch measurements were the same. What is it that you want to know? There is no question of testing. As dpi = pixels per inch then I can see resolution is 4800 ppi by 9600 ppi. Firstly, why the two numbers, I would have thought resolution needed only one number and secondly, if this sort of resolution is readily available why does the author of the book take pains to imply that 600 ppi is something important? Two numbers are because the resolution is higher in one direction than the other. 4800 ppi used to be marketing speak for a lower ppi with some math tricks to make it look higher (like scan the image multiple times at a low dpi and create a higher resolution surface). I don't know if they still pull that kind of thing. I have no idea what the author wants to imply, but few printers are capable of outputting more than 600ppi, and you are dropping below human visibility there. As for your original question. if you have 4800x9600 ppi, and you scan an inch square of material, you will end up with 4800x9600 pixels. Thus the question if you are having a laugh, as your question seemed trivial. Jeff -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain signature.asc Description: Digital signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] pixels to dpi
On Tue, Apr 07, 2009 at 03:37:57PM +0100, norman wrote: As for your original question. if you have 4800x9600 ppi, and you scan an inch square of material, you will end up with 4800x9600 pixels. Thus the question if you are having a laugh, as your question seemed trivial. I am really sorry you see my questions as trivial, they are not meant to be. Much of my difficulty is one of understanding the terminology used. Not a problem at all. Professionals get this kind of stuff wrong all the time. Yes, if you were to scan a 5 inch square image at 4800x9600 ppi, then you should get 24,000 x 48,000 pixels. So, something else is going on. Your hardware is only capable of 600dpi (I just looked it up on Canon's website), it can double sample in one direction to get close to 600x1200, then interpolate to get up to the ranges of 2400. So, it really doesn't make sense to scan any higher than your base of 600dpi. But that doesn't address the other problem you mentioned. 729 pixels / 5 inches is 149dpi, which is off by a factor of 4 from what the hardware is supposedly capable of and 16 from what you think you scanned at. I would make sure that the GIMP isn't loading some embedded thumbnail instead of the real image. If you are in windows, you should be able to right click on the image and go to properties. The size that Windows thinks the image is is usually stored in the Summary tab. If you are on a Mac, I would suggest using Preview, then there should be a view image info menu button somewhere (not near a mac at the moment). If you are on Linux, then you should be able to type file imagename.ext and get the file size. Please explain and, just in case you think I am some youngster trying to get his homework done, I was 81 years old last birthday. I didn't think that for one second. I assumed that unit conversion wasn't understood rather than that you were seeing something contrary to what the math tells you. I apologize. Jeff -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain signature.asc Description: Digital signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Batch convert .xcf to .xcfgz
On Wed, Feb 04, 2009 at 07:28:06PM +0100, GSR - FR wrote: Hi, capn...@yahoo.com (2009-02-04 at 0902.16 -0800): I have a large amout of .xcf that I would like to batch convert to .xcfgz is there an application that can do this? Just run gzip *.xcf in a shell. Or look for a compression app that can gzip multiple files separatelly (not tar then gzip... no idea if any app does that alone, I just go with simpler g(un)zip for this). As advice, save and use .xcf.gz instead of .xcfgz so you need no extra steps, gunzip *.xcf.gz will revert the compression, but with .xcfgz you will need some tricks to handle the renaming. The trick isn't hard once you know it gzip -S gz *.xcf (the default suffix is .gz, so we are just removing the .) Jeff -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain signature.asc Description: Digital signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] lossless cropping?
On Mon, Feb 02, 2009 at 01:37:24PM +0100, Claus Cyrny wrote: I have to admit that, after following this thread, I still have no idea what Zhang Wei Wu means by 'lossless 'cropping'. I understand' lossless compression', but cropping is by definition lossy (you remove part of the original image), so I don't know what 'lossless' means in this context. I'm going to take a wild guess on this (not having read the rest of the thread). If you were to take a lossy format (say, mp3 or jpeg), and cut out portions of the data and then recompresses the remaining data, the data that remains gets refiltered and suffers more loss than that just due to the data cropped out. On the other hand, both mp3 and jpeg support something that could be termed lossless cropping as long as you cut on the data boundaries (packet in mp3, 8x8 block on jpeg) where the data you crop out obviously gets thrown out, but the remaining data does not get refiltered with its resulting additional informational loss. Jeff -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain signature.asc Description: Digital signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Free textures
On Mon, Feb 02, 2009 at 01:29:18PM +0100, Claus Cyrny wrote: Could you check if this file is a valid zip file? Sorry, the file got corrupted somehow. I'm using Ubuntu's archive manager, and it seems that there's a problem with zip files. I now created a tar.gz archive. I'm not sure if utlilites such as WinZip support this, but currently I have no other option. (I could also try .jar, which I never used before). WinZip does support tar.gz JAR is just a zip file with some extra metadata I would be _shocked_ if you couldn't just zip this yourself. It isn't hard, if you want maximum compression... zip -9r ArchiveName.zip Directory_To_Be_Zipped Additional_Files_If_Needed Jeff -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain signature.asc Description: Digital signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] chromatic aberration
On Mon, Mar 17, 2008 at 03:09:47PM -0500, Chris Mohler wrote: On Mon, Mar 17, 2008 at 1:39 PM, norman [EMAIL PROTECTED] wrote: I have been copying some old colour transparencies using my digital camera and most of the images produced suffer from chromatic aberration somewhere within them. I have tried to find some procedure to remove these blemishes but, so far, have not found anything I can get to work. All suggestions and how to get round the difficulty will be gratefully received. Not having worked on this problem in particular, I don't really know. My first approximate guess would be to decompose the image into color channels and apply deblurring filters on the seperate channels. You should be able to make reasonable progress with this as as a first order approximation; all chromatic aberration is, is the different colors blurring different amounts. Jeff -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain pgpDSWEBTpzhb.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Bit-depth Processing
On Tue, Oct 02, 2007 at 11:58:47AM -0700, Greg wrote: --- Patrick Shanahan [EMAIL PROTECTED] wrote: Then you need to abandon the jpeg format as it is lossey (google for it) and you need to shoot RAW. I know, but if you can retain your original bit-depth, the lossyness isn't as noticeable, especially if you set the compression to the lowest possible. At least, that's my understanding. But, JPEG is only 8 bit (well technically it isn't even that, but I digress), so you aren't retainnig your original bit-depth -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain pgprgTiBvZ5sp.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Does GIMP support GEOTIFF files?
On Fri, Aug 24, 2007 at 03:29:49PM -0400, Kevin Cozens wrote: Maverick Merritt wrote: Does the GIMP support GEOTIFF files? If not, are there any plans to do so? The answer to both questions is no. It is unlikely that the file format would be supported in GIMP unless there is a publically available document which describes the file format. If there is such a document, it just takes an interested party to create a plug-in for the format. It has been almost ten years since I worked with GEOTIFF files, but IIRC they are just TIFF files with a couple extra tags telling you where the image is geospatially located. That should mean that GIMP can open a GEOTIFF fine, but there are no guarantees that it can keep the tags if you then save it. Note, I haven't checked this in a long long time, but it did work then. Jeff -- The man who does not read good books has no advantage over the man who cannot read them. -- Mark Twain pgpjfRSSVcshw.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Photos negatives scanned into the gimp
On Tue, Apr 17, 2007 at 11:16:28PM +0200, Sven Neumann wrote: Hi, On Tue, 2007-04-17 at 22:58 +0200, Axel Wernicke wrote: unfortunately it is not that easy, because not only have you to invert the colors, but to subtract the brown color from the film strip also. I'm not sure, but my first guess would be that this is not easily done in GIMP. It should be easy though to write a plug-in that does this. One just needs to figure out the right values. Perhaps there are ICC color profiles for common brands of negatives that could help with this task? XSane maintains a list of known values. Actually, most scanning software (including XSane) will fix it for you if you tell it you are scanning a negative. -- Hofstadter's Law states: It always takes longer than you expect, even when you take into account Hofstadter's Law. pgpCztPfkRCIB.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] problem saving as png
As he has repeatedly stated, the problem is under FF/Linux. There are many things in which FF/Win FF/Max and FF/Linux are different. It looks like FF/Linux isn't up to date with Gamma correction for some reason Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpPbMeBylJcJ.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] problem saving as png
On Mon, Jan 22, 2007 at 11:38:48AM -0800, Anthony Ettinger wrote: Create an html page with background-color of #9c0; then do the same with the image in GIMP, and save as PNG. I'm seeing color variation. I've tried that exact experiment just now, and see no variation. Perhaps you are doing something more that makes it a problem? http://broggs.org/~mcbeth/foo.html -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpzxGTzPON17.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] problem saving as png
On Mon, Jan 22, 2007 at 11:41:30AM -0800, Anthony Ettinger wrote: I made a test case: http://chovy.dyndns.org/gimp/test/green.html Looks like an IE6 bug. Firefox and Opera both show it as the same color. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpuXMVF9qWJn.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] delete a file
On Mon, Jan 08, 2007 at 08:11:08PM -0600, Bill Lee wrote: I use the Save As feature an awful lot. Am I missing something? Bill Lee I don't believe you are. That is exactly the feature she wants. My personal favorite is Save a Copy, it allows me to make edits to a file, and save off snapshots in time of my edits while keeping the original filename for future edits. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpGmQzsCXjSl.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] scanning electron microscopy
On Tue, Dec 12, 2006 at 03:48:13PM +0100, Michael Schumacher wrote: Von: dorai iyer [EMAIL PROTECTED] is there any plugin that allows calibration/scaling of the image pixels to microns or nanaometers. Try the unit editor. http://docs.gimp.org/en/gimp-xtns-unit-editor.html There appears to be a limitation on the unit editor that prevents it from being used for nanometers. If you type in the scale factor 2540, (which is appropriate for nm), the editor chops it down to 2^16. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] what is the most simple bit map file format
On Wed, Nov 08, 2006 at 05:16:02PM -0500, rob wrote: I wanted to understand a graphics file format... any format that could be disected with a programming language...any programming language. What is the absolute simplest bit map file format we can save out a black and white image in GIMP? I think it might be PPM in my version 2.2.6 but there may be somehing simpler for black and white images like what I look to end up with in making screen color seperations. Space is not an issue any more with 80 gig hard drives so compression is not needed any more. So leaving out ALL compressed graphics formats whats left? Interesting enoughASCII art is a SAVE AS option. I wonder how fine a grain of detail we get when saving as ASCII art. I have to play with that one. PPM is probably the simplest format to write your own reader for, but xbm would be the easiest to dissect in C, as an xbm is secretly just a C source file with an embedded char array you can simply include in your compile. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Best File Format For Scanned Images
On Wed, Oct 25, 2006 at 08:37:55PM -0400, Matthias Julius wrote: Alan Wolfe [EMAIL PROTECTED] writes: Just curious, is there a reason that PNG is a bad choice for this? Lossless compression seems like it'd be a great advantage and it isn't a fly by night file format. Does PNG support 16 bit per channel? If not then TIFF is probably the better choice for those. Yes, it does. I do medical diagnostic software, and we use the 16-bit support of PNG every day. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpmQnge0AMeu.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Some photograph morphing tricks
On Mon, Jul 31, 2006 at 11:34:10PM +0200, David Neary wrote: Hi, Tanveer Singh wrote: Great tutorial. But one hitch.In my case I want to make BW a small area. So I am guessing I need to interchange the layers. I.e color over BW. I would do this nice and simple. Make sure that you have the areas you want to be greyscale selected (either select them or select the color bits and invert the selection), then go to Colors-Desaturate Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpwcNmDmJMeo.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Re: GIMP can induce De Quervain's disease
On Fri, Jul 07, 2006 at 05:34:11PM +0200, Roel Schroeven wrote: There's one relatively simple change I can think of, that could reduce problems as the one experienced by Hector: instead of requiring the user to hold the mouse button pushed down during a drawing operation, it's possible to signal the start and the end of a drawing operation with separate mouse clicks. I.e. instead of mouse down - paint operation - mouse up you could do mouse click - paint operation - mouse click. Personally, I switched to a trackball and picked up contact juggling to exercise the wrists. Fundamentally, a mouse is the wrong tool with which to paint, and by and large a disasterous tool for computer health. Generally, the advice to take breaks is a good one. Specifically re the above quoted, I would consider mouse toggling to be an accessibility issue best dealt with at a desktop level (GTK/Gnome/Whatever) rather than application specific hacks. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpvahrDuG1xU.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] how to rotate ?
On Thu, Jun 29, 2006 at 03:48:48PM +0200, [EMAIL PROTECTED] wrote: Hello, I have a little rectangle which I like to rotate / animate. The rotation should give a kind of 3D impression - the backward going part is shrinking and the forward comming is growing relative to the middle axis which goes noth / south. I checked the GIMP help and asked google but I did not find a way to do this under linux with GIMP, just some expensive MS Windows solutions. Any hint how to do this are very wellcome. :-) I hope this is not too bad expained, my English leaves room for improvement - which I am working on. I used to do this all the time with Filter - Map Object Select box, you can rotate it at will, you'll need a bunch of layers (one for each frame), and you are mapping your image to the 3d object, so make sure it is something interesting (I just tested again with a simple pure red image, looked great as it span. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Re: Arrow
On Wed, Jun 28, 2006 at 11:29:02AM -0500, Ben Conley wrote: The pencil does draw very aliased lines (which I suppose is good sometimes, maybe.) but the tool next to it, the brush, does a very nice job. Select snip Way off topic, but in my art needs, I need non-anti-aliased (aliased) lines 99% of the time, since file size is a priority for me, and lossy compression is right out. Aliased lines make it easier for me to get down to the low-color count levels where if you are careful, you can get good looking picture, while getting phenominal compression out of PNG. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpvp1pfN7ch8.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] mebbe easy - replace car color but preserve highlights
On Fri, Dec 16, 2005 at 04:59:39PM -0200, Joao S. O. Bueno Calligaris wrote: Try using layers-Colors-HSV , and changing the hue. If there are other greens in the image, have the car selected first. I've had more success with the HSV mentioned above as I have had to match exact colors. In general, it is more flexible than the rotate palette option Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgp24z3N3ysaO.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Creating heightmap from a topographical chart
On Sun, Nov 27, 2005 at 01:00:56PM +0200, Vassilis Chryssos wrote: This is what I'm trying to achieve: I have a topographical chart (curves that depict the height of a territory) which I want to use as a heightmap for blender. Blender uses gradient grayscale images to raise the pixels of a plane according to the whiteness of each pixel (i.e. the white pixel will be raised to the higher level, whereas black pixel will remain to the bottom. The in-between pixels will be raised according to their value of white). With this in mind someone must create a grayscale gradient image out of the topographical chart. Could someone suggest a smart way to apply grayscale gradient to the image according to the height specified by the curves? Wow, um, yeah. I know what you are wanting to do, I'm just not sure the GIMP or even your source map are the right tools for the job. For the GIMP to be able to do something like that automatically, it would have to be able to distingush the isoclines from the river drainages, trail markings, text, etc. Then, once we know which are the isoclines, they would have to be closed (several of them are not), and it would have to have some way of telling which are heading up and which are heading down (which is only hinted at in places with the elevation text). Given that all this is unsurmountable by automated means, we turn to hand driven. Much the same way, you would need to remove everything that wasn't an isocline, and make sure that all the isoclines were closed. You could then select by region with a 0 threshold and fill each isocline with the appropriate color. That would leave the isoclines themselves to deal with, but when you were all done with the (very tedious process), you would have something that looks like your australia map. But, that won't get you to the blender map. You would end up with a terraced effect that would look very strange. You could use a blur to get rid of some of the terracing, but that isn't really whay you want (I don't think). Might I suggest finding out the latitudes and longitudes of the map you want to do, and downloading the DEM data for the region? The data is all available online (legally) for free if you look hard enough, and you should be able to find a high enough resolution for your needs. I personally have a copy of the DEM data for the Earth at a very low resolution (much, I'm sure, than would work for your map). And, I can send it to you so you can get an idea of what you would be looking at if you like. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpqAO3TJxf58.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Transparent Logos...
On Thu, Nov 24, 2005 at 11:12:52PM -0600, Jeff Avveduti wrote: Ok, I know this is silly... but I am a baby in Gimp. Please bear with me...and thanks to everyone who has been answering my question. That was what I was doing so that fixes that issue. Now, the instructions given is using a texture background. How can I just make a logo with a transparent background and then save it as mentioned above? New --- size, background transparent -- add text --- bump map--- now what? I don't see what I did? I know this is silly but Okay, one step at a time. New --- size, background transparent Text (Hello World) in white Dialogs - Layers - New Layer Filters - Render - Clouds - Plasma In the Layer Dialog, Click on the text layer (I move it to the top, too (up arrow on the bottom)) Filters - Map - Bump Map Select the Plasma layer as the bumpmap layer play with the parameters click okay You can then (if you are done with it) delete the plasma layer (or just hide it) I suspect that what may be tripping you up is the the GIMP doesn't get rid of the bumpmap layer after bump mapping, and it may be higher in the stack than your text. Perhaps just deleting or hiding that layer will give you what you want? Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpDgV6VU2305.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Transparent Logos...
On Thu, Nov 24, 2005 at 03:37:34PM -0600, Jeff Avveduti wrote: Yes but the background is white? Why is it so hard to save a transparent logo? It was transparent... but when saving it, the background is white. Probably because you are saving it in a format that doesn't support transparency, like JPEG. If you do that, it asks you to flatten the image, and will fill in transparency with the background color (more or less). If you want to maintain transparency, keep the logo in xcf, or png (they both support 8-bit transparency) Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpNI5JDklC5p.pgp Description: PGP signature ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Transparent Logos...
On Tue, Nov 08, 2005 at 08:52:24PM -0600, Jeff Avveduti wrote: I have tried searching for this but I am not finding quite the answer I hunger for. It is best to show you... www.avveduti.com/ebay/logo.jpg There is what I am wanting. To make a nice transparent logo in gimp. That was created in PS 7. A nice bevel edge with ability to change the light direction and the amount of bevel.. I made the text go to 0 opaque and voula.. there it is. Place your texture down (like the wavy red) Create a text layer (white for starters), and add your text Make sure the texture layer is selected, then go Filters - Map - Bump Map Play with all the fun knobs that do everything you asked for above. Click okay when you are done, then make the text layer invisible (click the eye) Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpgBsUGqLLMr.pgp Description: PGP signature
Re: [Gimp-user] Opening PNG images with offset as layers
On Wed, Oct 12, 2005 at 02:44:47PM +0200, Simon Budig wrote: Timo ([EMAIL PROTECTED]) wrote: On Thu, 2005-10-06 at 09:13 +0300, Timo wrote: I have PNG images which specify an offset (oFFs). When I try to open these as layers, Gimp ignores the offset and centers the image. Am I doing something wrong? Opening the images in normal way works as expected although Gimp could automatically make the canvas oversized so that it can hold the image. No answers yet. Am I too impatient or should I take this to an other list? The only thing I can tell you is, that there is code in the PNG plugin to handle offsets. I don't have any such images available, so I cannot verify this though. Incidentally, an easy way to create one is to use ImageMagick to crop the PNG. Last I checked, it stores the oFFs chunk, which when opening the image in GIMP, causes the layer to be offset. The issue at hand is that if you open the image as a layer (rather than as an image), the offset is ignored and the layer is centered. I would be interested to know if you have a selection when you open the image as layer, does it center the layer on the selection (it would be consistent with the floating layer's behaviour. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpP3rdLsHXlf.pgp Description: PGP signature
Re: [Gimp-user] Lanczos interpolation method
On Tue, Oct 11, 2005 at 01:38:43AM +0200, cedric GEMY wrote: Testing 2.3, i can there is new interpolation method called Lanczos. It is described as being better than cubic. Does anyboy know simply :) how it works with the picture ? Err, a quick summary (perhaps not simple) is that Cubic interpolation uses a third order polynomial to guess at values we don't have pixel samples for. Lanczos is from a family of interpolation schemes called windowed sinc. The sinc function is defined as sin(x)/x (with it being 1 at x=0). It shows up a lot in signal processing, and can be shown to be ideal for interpolation (for some definition of ideal). Since the real world isn't ideal, and all trigonometric functions introduce ringing in a non-ideal world, they window the sinc function to limit how far out the ringing can go. The sinc interpolation schemes tend to do a visually better job of interpolation at the cost of more processing time (but still less than a generic spline implementation). I'm glad they added it. I probably won't be personally using it much, since my requirements are elsewhere, but it is a very useful thing to have available. Incidentally, I know gamasutra had an article on sinc interpolation a few years back that should still be easy to find (I accidentally ran across it again a few weeks ago). Also, http://www.mathworld.com is a great resource for general math information. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpxEhahg5h0C.pgp Description: PGP signature
Re: [Gimp-user] Re: PNG binary transparency
On Wed, Sep 14, 2005 at 08:00:01PM +0200, Michael Schumacher wrote: IMO it could be a reasonable default to set tRNS to the currently selected background color when saving with keep tranparent pixels' color unset. This would copy the behaviour for the bKGD chunk. Except that would make any pixels with the background color transparent in any app that correctly parses tRNS. I seriously doubt there is a good automatic solution. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpwBrkCKHXNk.pgp Description: PGP signature
Re: [Gimp-user] Re: PNG binary transparency
On Tue, Sep 13, 2005 at 05:30:21PM +0300, Diaa Sami wrote: that's exactly what I wanted, I looked into PNG docs, and I found out that there are two functions responsible for this, which are png_get_tRNS and png_set_tRNS. Yup. For just about any chunk, there is a get/set pair in the reference implementation. The GIMP could easily figure out when the alpha is binary (to use tRNS rather than RGBA), but picking out an unused color to represent transparent that is acceptible to the user, applications, and further editing is an impossible (or difficult) task. IE ignores tRNS when you aren't in palette mode, anytime you added some of that color to an image, it would turn transparent seperate from what you expect, etc. ok, I'll use ImageMagick to do it. Glad I could help. -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpoXH6AJ27aA.pgp Description: PGP signature
Re: [Gimp-user] Re: PNG binary transparency
On Tue, Sep 13, 2005 at 04:26:39PM -0400, michael chang wrote: IE ignores tRNS when you aren't in palette mode, anytime you added some of that color to an image, it would turn transparent seperate from what you expect, etc. So logically, should we even be using tRNS in PNG anyway? IE is one of the most commonly used browsers, AFAIK... Absolutely. IE's PNG transparency support is broken. Has been, and will be for a long time. People can't ignore standards just because MS does. Plus, the question was for a file that will never see the light of day in IE. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgp8J9cEO0adO.pgp Description: PGP signature
Re: [Gimp-user] Re: PNG binary transparency
On Mon, Sep 12, 2005 at 06:04:59PM -0400, michael chang wrote: On 9/12/05, Diaa Sami [EMAIL PROTECTED] wrote: actually I need to do this with 24-bit PNG's, is it possible? it it's not, do u know any other free tool that does this? AFAIK GIMP doesn't support 24-bit colour. Apparently it's a limitation in GIMP's current design, and won't be fixed for a long time. Apparently, my e-mail from before didn't go out) GIMP definitely supports 24-bit color. This is 8-bits per channel (R,G,B). With an Alpha channel (more on that later) that is 32-bit color. GIMP does not support 16-bit per channel (48/64 bit color). Now that that is cleared up. Diaa, I have read your e-mail several times, and I don't have a clue what you are trying to do. Perhaps some clarification would be in order? I'm very familiar with the PNG format, having written and ported encoders/decoders for various projects. You can do binary transparency with 24-bit PNGs by thresholding the alpha channel. This will leave you with just on and off (255 and 0). This is under Layer - Transparency - Threshold Alpha If you want to convert a color to transparent, you want Layer - Transparency - Color to Alpha If what is really happening, is that your application has the old hack where a certain color represents transparent (usually olive or magenta), then just draw that color in the bits that you want transparent. It is up to your application to then render that color as transparent. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) ___ Gimp-user mailing list Gimp-user@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Re: PNG binary transparency
On Tue, Sep 13, 2005 at 06:06:14AM +0300, Diaa Sami wrote: first, I want to thank you for your long and clear response. well, you're asking about what I'm trying to achieve. what I want is to have somekind of transparent color which is written in the PNG file. I don't want to have an alpha channel, just that transparent color. I'm don't know the details of the PNG file format, but I almost sure it is possible, because IrfanView does it. if you want, download that IrfanView, and choose PNG as the saving file format, you'll find a checkbox called 'save transparent color'. Ahhh. tRNS I haven't looked at that chunk in a long time. Hmm, I hate to say it, but ImageMagick might be your best bet. I actually wasn't aware of this particular trick of using tRNS without a PLTE chunk in the image. Interesting. Yeah, create the image in GIMP with whatever the color you want to have be transparent in place, then in ImageMagick, run convert input.png -transparent color output.png My initial reaction was that it would be easy to patch the GIMP to mimic ImageMagick's behaviour, but it really is a can of worms having a color pretend to be transparent. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgp4OGrSn2Cvj.pgp Description: PGP signature
Re: [Gimp-user] Overlaying and scaling images
On Wed, Jun 01, 2005 at 11:38:23PM +0100, Dylan wrote: Hi All, I'm trying to overlay images of maps onto aerial protographs. Using the photo as a background, I need to scale and rotate the map image so that the two line up. Is this possible with the Gimp? What approach should I use? If it's not feasable with Gimp, does anyone know any (Linux) software which would be suitable? Definitely possible and feasable. As long as you have a simple perspective transform in your images. Once things like WGS'84 and other coordinate systems rear their head, the best bet is something made for this like GRASS. Anyway, the main tool you would be looking for is the Rotate, Scale, Shear, and Perspective tools (Shift-R, Shift-T, Shift-S, Shift-P by default) Perspective and Rotate will probably be the most useful. I've done it, and it works as long as your data isn't too distorted. Don't try anything like the overlays Google Maps does, though, you would definitely need something like GRASS then. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpxLe5crwnwQ.pgp Description: PGP signature
Re: [Gimp-user] Alpha Channel
On Wed, Apr 13, 2005 at 03:57:56PM +0100, David Marrs wrote: cedric wrote: I wonder why, when Opening or creating a document, there are only 3 color channel and then, when creatin a layer, the alpha is coming. What this stand for ? Cedric The bottom layer cannot be transparent, as far as I'm aware, so it does not have an alpha channel associated with it. You can still export transparent gifs and pngs though. Err, unless I am misunderstanding you, you are wrong. Bottom layers can most definitely be transparent. As noted previously in response to this question, when you create a new image, what you fill the base layer with changes whether or not it has an alpha channel. At any point, you can add an alpha channel by going to: Layer - Transparency - Add Alpha Channel At any point, you can remove an alpha channel by flattening the layer. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpP6G9fLk27B.pgp Description: PGP signature
Re: [Gimp-user] Lossless JPEG Crop
Your best bet for a lossless JPEG crop is to use ImageMagick or the JPEG utils rather than GIMP. IIRC, there has been talk about allowing GIMP to do the few lossless JPEG transforms that are possible, but I haven't seen patches or release notes to the effect. something like jpegtran -perfect -crop 50x50+23+10 input.jpg output.jpg Would do the trick BTW, even the guys that designed the JPEG library say that 100 should never be used (and it doesn't mean what everybody thinks it means either) Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpoc9ZVNtNCe.pgp Description: PGP signature
Re: [Gimp-user] gimp crashed while saving
On Sat, Mar 26, 2005 at 10:17:47PM -0500, Peter Jon White wrote: Hans Henrik Hansen wrote: This evening I installed GIMP 2.0 under SuSE 9.2/KDE3.3.0 I wanted to add some text layers to a .jpg-file - five layers altogether. When I attempted 'save as' GIMP crashed, and all my work was gone! :( One more attempt ended same way - finally I got through by saving one layer at a time! I am wondering if this is normal GIMP behavio(u)r?? There is a a couple known bugs in SuSE dealing with JPEGs. I can't imagine that being the problem since you are going to save this as a XCF so you keep your layer support, but SuSE updates for the JPEG libraries might still be worth looking into. Normal Gimp behavior seems to be to not work much at all. And normal behavior on the support forums seems to be to ignore requests for assistance. I'm sorry you feel that way. Since we are using anecdotal evidence, I haven't seen GIMP crash in quite some time, and I use it to do some pretty funky stuff on Windows, Mac OSX, and Linux. Whenever I have asked for help, and provided information on my problem, I have received prompt and knowledgable assistance. I try to do the same when I know the answer. I don't do any prepress work, so I'm not much help there. My specialties lie more with image formats, GIS, and machine vision. It's a good thing Photoshop works. Funny, it never has for me :) A little more seriously, if you are feeling that put upon, write me privately, and I will do my best to find you an answer. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpy8JpZ4wOnh.pgp Description: PGP signature
Re: [Gimp-user] Re: Default mode for file dialog
On Fri, Mar 25, 2005 at 01:11:16AM +0100, Sven Neumann wrote: There used to be a spec proposing a DND enhancement called Direct Save or XDS. I have not been able to locate that again but this is something that the file manager handling the desktop would have to implement. If there is a widely adopted standard for this, we will add support for it. Take a look at the ROX people. They were the ones pushing Direct Save. Those apps they have gotten to work wonderfully. http://rox.sf.net Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgp7rvFaSjEnz.pgp Description: PGP signature
Re: [Gimp-user] X an Y resolution
On Wed, Mar 23, 2005 at 11:17:51AM +1100, Malcolm Tredinnick wrote: On Wed, 2005-03-23 at 01:00 +0100, cedric wrote: When creating a new document, we have two fields. I've always used the same value but if they are 2 it is certainly because there is one. So does anybody know in what cases X and Y should be different ? Think about printable media (not just images for the screen). There are many printers that can print at different densities in the horizontal and vertical direction (e.g. 720 x 1440 dpi or 1440 x 2880) as there highest dot density. So if you were trying to work precisly, pixel-for- pixel, you might want to set the resolutions appropriately. Another simple case is after deinterlacing an image, the y pixel density will be half of what it was before, while x stays the same. In fact, it is very rare for monitors/LCD panels/CCD cameras/etc to really have square pixels. Pretending it is square may be close enough for the purposes of the Web, but for print media, medical equipment (my work), GIS (my old work) and other endeavours, x density = y density is inadequate and incorrect. In fact, even linear mapping is often insufficient. (I've had to use some pretty wild transforms in the course of work on images) Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpaA8oDePeKa.pgp Description: PGP signature
Re: [Gimp-user] Turning off dashed line around canvas.
On Fri, Feb 25, 2005 at 07:31:55PM -0500, Patrick Shanahan wrote: * Michael Schumacher [EMAIL PROTECTED] [02-25-05 19:19]: This is close to shooting yourself in the foot using Prolog, isn't it? :) Next you are going to tell everyone how old I really am grin Prolog can't be that old. I did tons of programming in it, and I'm a spring chicken :) Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpJNdHzFvlL6.pgp Description: PGP signature
Re: [Gimp-user] specify png background color?
On Sat, Apr 03, 2004 at 12:32:25AM -0800, Tom Williams wrote: Zhang Weiwu wrote: Hello. I have a png logo with alpha channel, it looks good on every browser excepte IE, which rander the alpha channel to a single color. I wish to set the optional png background color to be #222, the background color of the webpage where the logo is. In this case even IE failed to rander alpha channel the picture is still displayed with a not-very-ugly background. But how? Is it possible? (I am using GIMP pre-2.0) Erm, last I checked, you have your background color (in the color chooser) be what you want the PNGs background color to be, then when you save the PNG, you make sure Save Background Color is turned on. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) signature.asc Description: Digital signature
Re: [Gimp-user] Select contiguous regions tool (Z) Problems
On Fri, Jan 16, 2004 at 10:30:39AM +0100, Dave Neary wrote: Hi, Jeffrey Brent McBeth wrote: I have a layer with many disjoint shapes surrounded by transparency. To move the rectangles, I would select the tool (Z), make sure the threshold was at 255, and select transparent areas was off. Then I could click on the shape (which selected everything up to the transparency) and move it where I needed it. I'm afraid I haven't been able to reproduce this in the HEAD. There has been one change since 2.0 pre1 in the contiguous region selection, but that should only affect indexed mode. That may be it. I forgot to mention that the images I'm working on are in indexed mode. Could you open a bug against this and attach an example image which shows this behaviour? Will do. I'll come up with a smaller version than the image I'm using now Are you sure that the completely transparent areas are really completely transparent? Absolutely positive. I just rolled my install back to 1.3.23 and it works as expected. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
