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#106
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Is VLC 3.0.3 for Windows 7?
In article , Mayayana
wrote: | BMP is | uncompressed and Windows-specific. So up into the | | (So basically a RAW format.) | RAW refers to any one of a number of proprietary formats that conserve data recorded by the camera. It holds much more data than the standard file formats. more accurately, raw is the data directly from the sensor, before it's converted into an image (de-bayering + other processing). Those formats (PNG, GIF, JPG, TIF) are just different kinds of packages for a BMP. They all decompress to bitmaps -- rectangular grids of numeric pixel values. png, gif, jpg and tif are entirely different formats than bmp. I find RAW fascinating to work with because one can draw so much out. For instance, if the image is underexposed it can be brightened to bring out the colors in the image. With a bitmap you can't do that. If you brighten it you just make each pixel lighter. Each point in the image is already a fixed color value. of course you can do that with a bitmap, but the results will be nowhere near as good as with raw. So with RAW you can pick the best image available from the data before reducing it to a bitmap. that's because raw is 'undeveloped'. |
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#107
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Is VLC 3.0.3 for Windows 7?
In message , Mayayana
writes: "J. P. Gilliver (John)" wrote | BMP is | uncompressed and Windows-specific. So up into the | | (So basically a RAW format.) | RAW refers to any one of a number of proprietary formats that conserve data recorded by the camera. (You said above that BMP is also a proprietary format - well, you said it's Windows-specific, but that's more or less the same as proprietary.) It holds much more data than the standard file formats. Those formats (PNG, GIF, JPG, TIF) are just different kinds of packages for a BMP. They all decompress to bitmaps -- rectangular grids of numeric pixel values. I find RAW fascinating to work with because one can draw so much out. For instance, if the image is underexposed it can be brightened to bring out the colors in the image. With a bitmap you can't do that. I do not see how RAW is not what you are calling a bitmap. It might have more bits per pixel, but if it's coming from a pixel sensor, it's a bitmap. (And AFAIK no digital camera uses other than a pixel sensor - in fact I can't think what other sort there could be, if we're talking digital rather than film.) If you brighten it you just make each pixel lighter. Each point in the image is already a fixed color value. I can't see how it isn't in RAW, either. You can apply gamma-like curves - different for each of the three colours, if you wish - to do clever things with colours near either end of the histogram. But this applies whether RAW or bitmap (since RAW is a bitmap). [Also - does it stand for something? If not, I'd call it raw, rather than RAW. Meaning raw (uncompressed) data.] So with RAW you can pick the best image available from the data before reducing it to a bitmap. IT IS A BITMAP! Unless it's a very fancy camera that has taken several images (bitmaps) at different exposures (and in extremis focuses). So it's either a bitmap, or a collection of bitmaps - nothing magical. [] -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf Tact is the ability to describe others as they see themselves. -Abraham Lincoln, 16th president of the U.S (1809-1865) |
#108
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Is VLC 3.0.3 for Windows 7?
I presume it became so when memory cards were very small, and had become
established when they became bigger - or, the problem never went away because "megapixel envy" means sensor size _in pixels_ kept growing (roughly keeping pace with card capacity). [My favourite camera has a 3.2 MP sensor - and I usually have it set to 1.] Back in the Dark Ages we had one of the first Kodak digital cameras that used a 3.5" diskette as the storage medium. You had a choice of saving the image as RAW or JPG, but not and. If one chose JPG then two files were generated, one with the actual image and one with the exposure data. I forget what the resolution was, and it took a significant time to process and store the image. Its burst mode was three frames only. Still, it was nice for snapshots and being able to have the images available right away as opposed to film. We did still shoot 35mm with my trusty Pentax, and Walmart had the option to both have prints made and have the negative scanned so you could download it. |
#109
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Is VLC 3.0.3 for Windows 7?
In article , Tim
wrote: Back in the Dark Ages we had one of the first Kodak digital cameras that used a 3.5" diskette as the storage medium. that would have been a sony mavica. https://3.img-dpreview.com/files/p/E...1323663/mavica 71b.png |
#110
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Is VLC 3.0.3 for Windows 7?
In article , J. P. Gilliver (John)
wrote: It holds much more data than the standard file formats. Those formats (PNG, GIF, JPG, TIF) are just different kinds of packages for a BMP. They all decompress to bitmaps -- rectangular grids of numeric pixel values. I find RAW fascinating to work with because one can draw so much out. For instance, if the image is underexposed it can be brightened to bring out the colors in the image. With a bitmap you can't do that. I do not see how RAW is not what you are calling a bitmap. It might have more bits per pixel, but if it's coming from a pixel sensor, it's a bitmap. (And AFAIK no digital camera uses other than a pixel sensor - in fact I can't think what other sort there could be, if we're talking digital rather than film.) raw is not a bitmap. in fact, raw is not an image at all until it's processed into one. each 'pixel' (actually a sensel) is not an rgb triplet, but rather only one component (ignoring foveon which is even more of a mess to process). at a minimum, raw needs to be de-bayered to convert it into rgb and may also need lens adjustments and other processing. [Also - does it stand for something? If not, I'd call it raw, rather than RAW. Meaning raw (uncompressed) data.] raw is not an acronym, but it's capitalized for some reason. |
#111
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Is VLC 3.0.3 for Windows 7?
J. P. Gilliver (John) wrote:
I do not see how RAW is not what you are calling a bitmap. It might have more bits per pixel, but if it's coming from a pixel sensor, it's a bitmap. (And AFAIK no digital camera uses other than a pixel sensor - in fact I can't think what other sort there could be, if we're talking digital rather than film.) You might want to find an article on RAW and see if it describes the orientation of the data. It's possible the layout is a Bayer pattern matching the sensor itself. https://en.wikipedia.org/wiki/Bayer_filter https://www.adobe.com/digitalimag/pd...rawcapture.pdf Paul |
#112
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Is VLC 3.0.3 for Windows 7?
In article , Paul
wrote: I do not see how RAW is not what you are calling a bitmap. It might have more bits per pixel, but if it's coming from a pixel sensor, it's a bitmap. (And AFAIK no digital camera uses other than a pixel sensor - in fact I can't think what other sort there could be, if we're talking digital rather than film.) You might want to find an article on RAW and see if it describes the orientation of the data. orientation is a tag in the data, not part of the format, and requires an orientation sensor in the camera, which just about all digital cameras do. old digital cameras (and possibly disposables) might not. It's possible the layout is a Bayer pattern matching the sensor itself. that's not only possible, but pretty much guaranteed, as just about every digital camera uses a bayer sensor. |
#113
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Is VLC 3.0.3 for Windows 7?
In article , Wolf K
wrote: because the software used to view it ignores the orientation tag. in other words, it's buggy. False. nope. |
#114
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Is VLC 3.0.3 for Windows 7?
"J. P. Gilliver (John)" wrote | (You said above that BMP is also a proprietary format - well, you said | it's Windows-specific, but that's more or less the same as proprietary.) | I wouldn't call it proprietary. It's the basic storage format for pixel data. A BMP only has a few bytes of header, describing the size, color depth, etc. The rest is just the map. A grid of pixel values. So, for instance, if the first 3 pixels in the upper left of a 24-bit bitmap are red then the bytes will start with FF 00 00 FF 00 00 FF 00 00 (Each pixel being represented by bytes for RGB.) And you can know the file size. It's the header plus 3 bytes per pixel. So the bytes representing a 24-bit image 10x10 would be 10 x 10 x 3, or 300. Except for the header, it's just numeric pixel values in a long string. Stop me if you already know all this..... The bitmap is the basic storage method of the data for display onscreen. Those 3 red pixels have to be painted to the screen. They're painted by telling Windows the bytes that make up the rows of the image pixels. Whether the 3 red pixels are in a PNG, JPG, or whatever, that format has to be unpacked to get a device independent bitmap (the pixel bytes) to paint onscreen. I imagine Mac and Linux must have something similar because it's the most basic form of the image data. They have to deal in bitmaps just llike Windows does, if they want to display or print images. But I don't know what their equivalent is. They could do something like store the bytes in reverse order -- 00 00 FF rather than FF 00 00 -- but it would still be a record of pixel values nonetheless. There's no image as such in JPG bytes. | | I do not see how RAW is not what you are calling a bitmap. It might have | more bits per pixel, but if it's coming from a pixel sensor, it's a | bitmap. (And AFAIK no digital camera uses other than a pixel sensor - in | fact I can't think what other sort there could be, if we're talking | digital rather than film.) | You may know more about it than I do. I don't really understand how the camera sensor works. And some camera sensors may actually record in RGB. But even if they do, it's more image data than a 24-bit RGB pixel value, and it's stored using a company's own method, related to the functioning of the sensor hardware. It can only be edited using software designed to deal with that particular RAW format. A bitmap is the currency of digital images for display or printing. Whatever the sensor has recorded, it has to be reduced to get the bitmap pixel bytes. Some of the descriptions compare RAW to a negative, which has all the recorded image data and then can be used to print the data as desired, changing the resulting photo by exposing the paper for more or less time and leaving it in the developing bath for more or less time. That doesn't seem like a good analogy to me, but maybe it's as close as it can get. The resulting photo is a little like a bitmap in the sense that each point of color in the photo has been locked into a single hue. I guess the big difference would be that the photo resolution is much higher than a typical pixel image. | If you brighten it you just make each pixel lighter. | Each point in the image is already a fixed color value. | | I can't see how it isn't in RAW, either. You can apply gamma-like curves | - different for each of the three colours, if you wish - to do clever | things with colours near either end of the histogram. But this applies | whether RAW or bitmap (since RAW is a bitmap). | An example that I find useful: The first time I tried taking a RAW image it was of a cyclamen in a dimly lit room. The picture was mostly just shades of gray. With a RAW editor I was able to pull out the green leaves and magenta blossoms, as though I had added a light to the scene after the fact. If that camera shot had been a JPG then it would have just been a bitmap.... and a poor one at that. The shades of gray would have been all I had to work with. A grid of grayish dots. If the magenta showed as a slightly pinkish gray then I could saturate that with red. But that color wouldn't be in the image. I'd be painting it on. | [Also - does it stand for something? If not, I'd call it raw, rather | than RAW. Meaning raw (uncompressed) data.] Yes. I think it's just called RAW to denote a file format. The file extension can be different, but RAW indicates one of those raw image formats. .... I don't think there's any rule about it. I'm sure you can call it "raw" if you want to. | | IT IS A BITMAP! Unless it's a very fancy camera that has taken several | images (bitmaps) at different exposures (and in extremis focuses). So | it's either a bitmap, or a collection of bitmaps - nothing magical. See above. It's not a bitmap and it's not a series of bitmaps. But I don't have the technical know-how to say exactly what the difference is. I only know that a bitmap stores color values for pixels while a RAW file stores much more data. It's magical to me, because I know the frustration of trying to coax a decent image out of limited data. |
#115
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Is VLC 3.0.3 for Windows 7?
In message , Mayayana
writes: "J. P. Gilliver (John)" wrote | (You said above that BMP is also a proprietary format - well, you said | it's Windows-specific, but that's more or less the same as proprietary.) | I wouldn't call it proprietary. It's the basic storage format for pixel data. A BMP only has a few bytes of header, describing the size, color depth, etc. The rest is just the map. A grid of pixel values. So, for instance, if the first 3 pixels in the upper left of a 24-bit bitmap are red then the bytes will start with FF 00 00 FF 00 00 FF 00 00 (Each pixel being represented by bytes for RGB.) And you can know the file size. It's the header plus 3 bytes per pixel. So the bytes representing a 24-bit image 10x10 would be 10 x 10 x 3, or 300. Except for the header, it's just numeric pixel values in a long string. Stop me if you already know all this..... Stop (-: [] | I do not see how RAW is not what you are calling a bitmap. It might have | more bits per pixel, but if it's coming from a pixel sensor, it's a [] You may know more about it than I do. I don't really understand how the camera sensor works. And some camera sensors may actually record in RGB. But even if they do, it's more image data than a 24-bit RGB pixel value, and it's stored using a [] Having read the two articles that Paul pointed us at, it seems that the situation is somewhere between what the two of us thought. Apparently most sensors are RGB, but have twice as many G sensors, arranged thus: RGRGRGRG GBGBGBGB RGRGRGRG RG GBGBGBGB or in other words, made up of GB quartets. (Some apparently now use different filters, such as CMY.) They also - as I'd already said - in general store more than 8 bits per element. So it's still a bitmap, but the green at least has more resolution. (Similar to the habit in some video circuitry - reflecting the response of the human eye - of "luminance on green".) How you convert this into normal RGB - which you have to do to actually _use_ it; after all, the R and G parts have only the resolution of the quartets - involves assorted compromises, in particular to avoid edge effects. The two articles Paul found do a good job explaining (I found the second one easier to follow, though I _think_ both included all the information). -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf A sleekzorp without a tornpee is like a quop without a fertsneet (sort of). |
#116
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Is VLC 3.0.3 for Windows 7?
In article , J. P. Gilliver (John)
wrote: | I do not see how RAW is not what you are calling a bitmap. It might have | more bits per pixel, but if it's coming from a pixel sensor, it's a [] You may know more about it than I do. I don't really understand how the camera sensor works. And some camera sensors may actually record in RGB. But even if they do, it's more image data than a 24-bit RGB pixel value, and it's stored using a [] Having read the two articles that Paul pointed us at, it seems that the situation is somewhere between what the two of us thought. Apparently most sensors are RGB, none are rgb. even foveon sensors, which falsely claims to be rgb, are not. but have twice as many G sensors, arranged thus: RGRGRGRG GBGBGBGB RGRGRGRG RG GBGBGBGB or in other words, made up of GB quartets. (Some apparently now use different filters, such as CMY.) otherwise known as a bayer pattern, and cmyg hasn't been used in a long time. They also - as I'd already said - in general store more than 8 bits per element. the sensor is an analog device and doesn't store bits. it generates an analog voltage proportional to the light hitting it, which is then quantized by the adc, from 8 to 16 bits per component. the more bits in the adc, the wider the dynamic range of the image. So it's still a bitmap, but the green at least has more resolution. (Similar to the habit in some video circuitry - reflecting the response of the human eye - of "luminance on green".) it's not a bitmap, nor does it work the way you think it does (no quartets). How you convert this into normal RGB - which you have to do to actually _use_ it; after all, the R and G parts have only the resolution of the quartets myth. bayer does *not* work by quartets, which would look like ****. bayer processing is *far* more complex, with spatial resolution only slightly less than a monochrome sensor. - involves assorted compromises, in particular to avoid edge effects. everything involves compromises. The two articles Paul found do a good job explaining (I found the second one easier to follow, though I _think_ both included all the information). they were very basic and did not cover the wide variety of bayer algorithms. |
#117
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Is VLC 3.0.3 for Windows 7?
"Frank Slootweg" wrote in message
news NY wrote: "Frank Slootweg" wrote in message news I don't know if all cameras and phones get it right, but our cameras [1] do get it right. They do not only sense the orientation of the camera, but also the movement. So I can turn the camera 90 degrees clockwise or 90 degrees counter-clockwise and it will detect correct portrait mode in both cases. (I've not been so silly to hold it upside-down for landscape, but it will probably get that right as well.) My problem is that whereas there is an obvious right way up for the phone in portrait mode (with the phone name at the bottom and the writing the correct way up!), there's no right and wrong way once you rotate the phone into landscape. I can never remember which way is right (no rotation needed) and which is wrong (180 degree rotation needed). Inevitable if I've taken various photos, some will be one way and some will be the other. It would be easier if the screen showed some text that did not rotate so it was always the correct way up, so I'd be consistent. Sorry, but I don't get your problem. AFAICT, it's the same situation as the upside-down real camera. I just checked on my smartphone and as I expected, it also gets this right. I.e. for both speaker-right/ microphone-left and speaker-left/microphone-right, a landscape picture has the correct orientation, i.e. 'ground' at the bottom, 'sky' at the top. That is, because - as I mentioned - the device doesn't only sense orientation, but also movement. Perhaps you can fool it by quick or/and akward movements, but in normal use they haven't failed me. I was meaning that unless you have viewer/player software that honours EXIF rotation flags for stills and video, you need to rotate it manually. And you need any editing software to preserve the flags when saving a modified copy or else perform the rotation to the correct orientation. I've just taken a couple of photos with my Samsung camera held in portrait and landscape, and the loaded them into various image-editing packages. And most *do* honour the flag. My mistake. I'm wondering if I never tried it because the photos were displayed wrongly in Windows Explorer so I *assumed* (not a good idea) than all programs would display them that way. Paint Shop Pro 5 is the only one which does not honour the flag. PSPX (V10.01), PSP X8, Photoshop Elements 7 and Photoshop Elements 11 all rotate photos correctly, even though in some cases the preview image-selection dialog box may display them wrongly - that dialog box may be produced by Windows rather than the application. The same is true of photo taken with my Canon SX260 compact camera and my Nikon D90 SLR. I've learned something new today. Thank you! I have noticed a "funny". In PSP X8 the Image Information for the images which are open (and displayed correctly) both say Orientation=Landscape" in the EXIF Information tab, and both give the image size as 2848x4288, irrespective of whether the image is portrait or landscape. Photoshop Elements 11, File | File Info | Camera Data doesn't explicitly mention the Orientation flag. Again the width and height are the same for both orientations, not exchanged for portrait versus landscape. |
#118
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film vs CMOS
"Phil Hobbs" wrote in message
... But why can't we use a bigger film then? Should we always compare 135 film against CMOS sensors of different size? A bit of possibly useful discussion: https://electrooptical.net/News/photographic-film/ One other factor to bear in mind: the depth of field varies with lens focal length, not field of view of the subject. This means that if you take a photo on 120 film and on 35 mm, with appropriate focal lengths of the two lenses to give the same field of view of the subject in both cases, and use the same aperture, the DOF will be less on the 120 photo than the 35 mm photo. So if 80 mm gives a certain field of view on 120 and 50 mm gives the same field of view (ie shows the same extent of the subject) on 50 mm, and both lenses are at f 4 (and so both will use the same shutter speed for the same speed of film), the 120 photo will have a shallower DOF. That is why it is so difficult to get shallow DOF on a compact or phone camera, because the lens is such a short focal length to suit the very small sensor, that almost everything is in focus even at a wide aperture (and the lens might have more artifacts and aberrations than the comparable lens that gives the same field of view for a 35 mm camera). In all this, I'm talking about the field of view of the *subject* - ie how much of the subject (wide/telephoto) is included within the frame of film or the sensor. This is why some drama TV programmes are shot on 16 mm or with a similar size CMOS sensor, but with a 35 mm-format movie camera lens and an intermediate ground-glass screen. This allows a shallower DOF to be achieved for artistic reasons without having to open up the (16 mm format) lens to a wider aperture which might show more lens flaws. The lens for 35 mm format produces an image on the ground-glass screen that has a certain field of view and depth of field which would be recorded on 35 mm film. The 16 mm camera focuses that image (which is all at one plane) onto 16 mm film. I wish I could find a URL that describes it, but I'm obviously not feeding Google with the correct search keywords - a common problem I have. |
#119
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Is VLC 3.0.3 for Windows 7?
"J. P. Gilliver (John)" wrote
| So it's still a bitmap, but the green at least has more resolution. | (Similar to the habit in some video circuitry - reflecting the response | of the human eye - of "luminance on green".) | | How you convert this into normal RGB - which you have to do to actually | _use_ it; after all, the R and G parts have only the resolution of the | quartets - involves assorted compromises, in particular to avoid edge | effects. I still don't really understand that. It sounds like you have experience with optics. I understand what a bitmap is and how it works. Even after reading articles I can't explain the actual mechanics of RAW image storage. Whether to call that a bitmap is, I suppose, a matter of terminology. I guess "bitmap" is actually outdated, since it's really a byte-based pixel map. But bitmap is a standard term in Windows programming. It's not just any image data. It's specifically defined and is specifically not JPG, TIF, GIF, or RAW file data. The string or array of file bytes defining pixels from 2 colors to 24-bit color is the only thing normally referred to as a bitmap. It's central to computer raster graphics functionality. And there's good reason for that: A bitmap in that definition is the way that digital images can be worked with/printed/displayed. The other forms -- various file formats -- are storage vehicles for that bitmap data. Whether you want to see it onscreen or edit it, you're always dealing with that string of bytes that represent a grid of color points. The rest is packaging. And in that sense, RAW is a different animal. It's not a package for an RGB bitmap that can be displayed onscreen or edited with standard computer graphics software. I think that's an important concept to understand in order to understand how other image formats fit in. Not understanding it accounts for much of the reason that even photographers are often attached to JPG. They don't understand the image format landscape or what an image is in terms of digital computing. I used to sometimes get into debates about this in a photo group. One of the photographers was very talented, but a strong Mac partisan and not so experienced with computers. He insisted that bitmaps were outdated and a Windows invention, simply because Macs don't have BMP files. He thought I was "obsessed" with bitmaps. I couldn't get it across to him that a JPG holds a bitmap. He thought of it as a more modern, more sophisticated, kind of image. |
#120
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Is VLC 3.0.3 for Windows 7?
"Mayayana" wrote in message
news I used to sometimes get into debates about this in a photo group. One of the photographers was very talented, but a strong Mac partisan and not so experienced with computers. He insisted that bitmaps were outdated and a Windows invention, simply because Macs don't have BMP files. He thought I was "obsessed" with bitmaps. I couldn't get it across to him that a JPG holds a bitmap. He thought of it as a more modern, more sophisticated, kind of image. I'd say that "bitmap" is synonymous with "raster": ie as distinct from vector. It is a generic term for an image that is made up of a rectangular grid of pixels, each with a certain brightness (or RGB triad of brightnesses). Windows rather hijacked that meaning by inventing a non-compressed file format which consists of exactly width x height samples (eg at 8 or 24 bits depth) with no run-length or JPEG compression. Sun had a very similar format called RAS (raster) which is totally uncompressed. I hadn't realised that Macs didn't have an equivalent, though I imagine it would be very easy for an app to have a module that could read/write .bmp or .ras files if required. Does it have any bitmap/raster file format that is lossless, either by being uncompressed or else using a lossless compression algorithm. |
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