If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Rate Thread | Display Modes |
#16
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
In message , Mayayana
writes: "J. P. Gilliver (John)" wrote | That's true for lossless. But the cropping itself is always destructive. | | Other than that cropping obviously removes information, what do you | mean: I thought the non-destructive crop was just that (in the part of | the image you keep, obviously). Being as it (as implemented in | IrfanView, anyway) crops to the nearest 16 (I think it's 16) pixel | boundary. I assumed the reason it does that is t avoid loss. | It's a clever method, but in general editing JPG is lossy. How often will one need to crop to the nearest 16 pixels but have no reason to do other editing? If one will do other editing then the image should be taken out of JPG format. So it's a kind of silk purse from a sow's ear thing. Often, an image is only available as a .JPG: it might have been received in an email as such, or downloaded from a website; or, the majority of cameras other than those sold for the serious professional (with appropriate pricetags) do _not_ offer raw bitmap formats. (They sometimes offer three _quality_ levels.) Nospam was just arguing, splitting hairs. It's really all he does. Well, we all - including you and I, definitely - dislike imprecision, especially if it actually results in an untruth being stated (even if unintentionally). What level of simplification versus imprecision is acceptable, varies from person to person and between situations: in other words, one man's desire for precision is another man's hair-splitting. I can't say I've registered nospam as _particularly_ irritating in that respect, but that's mainly because I tend not to remember people's levels unless they're _particularly_ irritating (in which case I'm likely to killfile them, and haven't with him yet), so you _may_ be right. | IMO, BMP should only be used when a software doesn't support a better image | format. How it stores 24bpp image pixels is unacceptably wasteful. Re-reading that, I do agree it's oversimplifying - there _is_ no better format _in terms of accuracy_. | | In what way - does it use two 16-bit words, or something? Or do you just | mean it doesn't do any (even lossless) data-compression? It has no compression. It's very straightforward. In general a BMP will be a 24-bit, uncompressed I was giving the benefit of the doubt: I thought he might have meant he'd found a case where it used 4 bytes to store the 3 byte information, or something. If he just means it does no lossy compression, I'd agree with you; if he means it does no loss_less_ compression, then he should have made it clearer that that' what he was referring to. image. (There are other options, but they're no longer used as far as I know.) The header looks [] I _think_ the two-level (one _bit_ per pixel) form is still supported (e. g. by IrfanView), though I'm not sure if it includes a palette for the two colours. (I _think_ GIF does have such [and 2- and 4-bit - 4 and 16 colour - modes.) That's what all raster images are. Pixel grids. Bitmaps. [Long section snipped - I presume written for readers other than me.] They're all just ways to store a BMP. None of those image formats means anything until the BMP is extracted. One can't render a JPG onscreen any more than the words of a ZIPped Word DOC can be read from the ZIP bytes. Good analogy! (Though I'd have probably said text file.) It has to be decompressed to get the BMP. Similarly, when one applies filters in an editing program it's just a math formula applied to the bitmap bytes. Sharpening increases the difference between the numeric values. Interpolation for resizing calculates a new pixel grid by examining the values of neighboring pixels. Lightening increases the byte values of the pixel bytes. It's all just math operations on 3-byte RGB pixels stored as grids in a BMP. In other words, the idea that BMP is outdated is a misunderstanding of what raster images are. Well, I'm not sure if PNG can be lossless. (Actually, I'm not sure if JP[E]G can; I know the quality slider in IrfanView can be pushed up to 100%, but I think that still involves some loss.) Then, of course, there are vector images (like good old HPGL, as well as more modern ones) - let alone fractals! But for actual pictures taken with a camera, they're all going to be bitmap rasters in the first place anyway. [Actually, use of the word raster reminds me: true rendering of *archive* _video_ material (i. e. shot with a CRT camera) ought to involve a _slightly_ slanted raster - which, I think, no modern rendering does.] -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf And every day in Britain, 33 properties are sold for around that price [a million pounds or so]. - Jane Rackham, RT 2015/4/11-17 |
Ads |
#17
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
In article , J. P. Gilliver (John)
wrote: Well, I'm not sure if PNG can be lossless. of course it can. (Actually, I'm not sure if JP[E]G can; I know the quality slider in IrfanView can be pushed up to 100%, but I think that still involves some loss.) https://en.wikipedia.org/wiki/Lossless_JPEG |
#18
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
"J. P. Gilliver (John)" wrote
| What I meant was: once an image has been reduced to 256 colours, then | any editing _that did not change the number of colours_ (such as | brightness or _possibly_ contrast tweaking) would not result in further | corruption if saved as GIF; once it's been reduced to 256 colours, then | anything further you do to it, _provided it doesn't result in an | increase in the number of colours_, can still be saves as GIF without | further degradation. I guess that's true. It works when doing things like diagrams. But I find that anything more complex, even a screenshot, really needs to be kicked back up to 24-bit color if I want to work on it. For instance, brightening a screenshot. That will need more than 256 colors to do. So I have to revert back to 24-bit and then resave it later. | I find it kind of ironic when this topic comes up. | I don't think I've ever heard you say this, but whenever | I talk about conserving space on disk, many people | will respond with, "Ah, that's not worth the trouble. | Disks are so cheap these days!" Yet when it comes | | No, you'll rarely hear me say that, as I come from the bygone era (my | first computer had 1K of memory; before that, the first one I worked on | had 16 memory locations). I will _sometimes_ concede that view when | discussion of time versus resources comes up, but given the choice and | time, I'll go for saving space where practicable. (Actually, more in MP3 | files than images; my eyesight, touch wood, has not deteriorated with | age other than the ability to close-focus, but my hearing _has_ lost | top, and/or I haven't had speakers capable of great top for some time.) | I wish I could switch with you. I don't listen to music in general and usually keep the audio turned off on my computer, but my eyesight is getting worse. I recently mounted my monitor on a drawer slide because I was leaning forward so much it was hurting my neck. now I just sit down and pull the monitor toward me... So I can't lean forward. Though I'm not sure what the radiation from that close display might be doing to my eyes. | When you say they want "vacation photos to fit on disk", do you mean "to | fit on _a_ disc", i. e. to make a CD (or, I guess these days, a DVD), to | give to friends/relatives? No I just meant that a lot of people are constantly taking 10MB phone shots and then want to save them on their computer. The people who complain that they need to buy a 4 TB hard disk because the 2 TB is full. They don't edit. They don't cull their collection. They also don't resize the images for better storage. They don't really get the system. They just think of it as "photos" that came from their phone and went onto their hard disk. It's like the people who invite you for dinner and have a 7' high bookcase full of photo albums. ("These 3 albums are little Ricky's christening. Wait'll you see! And it was so cheap at the drugstore to get all the shots printed!") For someone like that, who's not familar with file formats and doesn't edit photos, a BMP would just be a JPG that's very big. They wouldn't see the point. | (I remember using a Sony camera at work, that had a floppy drive built | in - and you could get several pictures on, of acceptable quality! [That | camera also had something I've never seen before or since: the ability | to use ambient light to backlight the display.]) Wow. 1.44 MB? They must have been small images. But I suppose they were also 256 colors? |
#19
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
"J. P. Gilliver (John)" wrote
| Well, I'm not sure if PNG can be lossless. https://en.wikipedia.org/wiki/Portable_Network_Graphics Portable Network Graphics is a raster graphics file format that supports lossless data compression. | (Actually, I'm not sure if | JP[E]G can; I know the quality slider in IrfanView can be pushed up to | 100%, but I think that still involves some loss.) Yes. It's not 100%. It's just an arbitrarily standardized scale of 0-100. Or sometimes 100-0. (In some programs I might save at 85 while in others at 15.) I have limited experience with photography, but I have got into RAW images. Better cameras seem to offer TIF format for images. The best offer RAW. Very interesting stuff. It somehow records the sensor data rather than pixels. So you can push and pull the data to what you need before reducing it to pixels. The first time I tried it, I took a picture of a cyclamen in a dimly lit room. I was able to pull out acurate green and magenta hues color in RAW. If it had been JPG or TIF I would have only been able to get brighter pinkish greys instead of magenta. |
#20
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
In message , Mayayana
writes: [] recently mounted my monitor on a drawer slide because I was leaning forward so much it was hurting my neck. now I just sit down and pull the monitor toward me... So I can't lean forward. Though I'm not sure what the radiation from that close display might be doing to my eyes. CRT or LCD? | When you say they want "vacation photos to fit on disk", do you mean "to | fit on _a_ disc", i. e. to make a CD (or, I guess these days, a DVD), to | give to friends/relatives? No I just meant that a lot of people are constantly taking 10MB phone shots and then want to save them on their computer. The people who complain that they Yes; I've yet to buy (or use at work!) a digital camera where one of my first actions is to change the default resolution to other than the maximum. (I use higher resolution when I _need_ it.) But I'm very much in the minority in this: virtually everyone I know takes all pictures at maximum resolution. need to buy a 4 TB hard disk because the 2 TB is full. It's not just the storage space needed: needlessly big images take a lot longer to load, and then to zoom, pan, and so on. But we dinosaurs haven't grasped the point: technology will just improve the speed of processors, and the size and access speed of storage, such that such considerations become irrelevant. Which I have to accept, though I hate. They don't edit. They don't cull their collection. They also don't resize the images for better storage. They don't really get the system. They just think of it as "photos" that came from their phone and went onto their hard disk. It's like the people who invite you for dinner and have a 7' high bookcase full of photo albums. ("These 3 albums are little Ricky's christening. Wait'll you see! And it was so cheap at the drugstore to get all the shots printed!") For someone like that, who's not familar with file formats and doesn't edit photos, a BMP would just be a JPG that's very big. They wouldn't see the point. And for the use they're putting them to, there wouldn't _be_ a point (in keeping bitmaps). Their pictures are probably looked at no more than [insert your number of choice here; I'd say between 5 and 10] times. | (I remember using a Sony camera at work, that had a floppy drive built | in - and you could get several pictures on, of acceptable quality! [That | camera also had something I've never seen before or since: the ability | to use ambient light to backlight the display.]) Wow. 1.44 MB? They must have been small images. But I suppose they were also 256 colors? I can't remember. It _was_ some time ago! The novelty at the time was the fact that it _had_ the built-in drive; the novelty looking back, was the ability to turn the backlight off. I don't _think_ they were 256 colours, though I'm pretty sure they _were_ JPEG, so not _that_ small. (I think it might have been 1 or 2 megapixel [though for the uses we had, I suspect I selected VGA a lot of the time].) -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf The first objective of any tyrant in Whitehall would be to make Parliament utterly subservient to his will; and the next to overturn or diminish trial by jury ..." Lord Devlin (http://www.holbornchambers.co.uk) |
#21
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
In article , J. P. Gilliver (John)
wrote: No I just meant that a lot of people are constantly taking 10MB phone shots and then want to save them on their computer. The people who complain that they Yes; I've yet to buy (or use at work!) a digital camera where one of my first actions is to change the default resolution to other than the maximum. (I use higher resolution when I _need_ it.) But I'm very much in the minority in this: virtually everyone I know takes all pictures at maximum resolution. with very rare exception, always shoot at maximum resolution. you can always downsize later. reshooting images at a higher resolution is anywhere from difficult to impossible. need to buy a 4 TB hard disk because the 2 TB is full. It's not just the storage space needed: needlessly big images take a lot longer to load, and then to zoom, pan, and so on. only if you have a very slow mechanical drive. with an ssd, there is no perceptible delay, even for *very* large images. But we dinosaurs haven't grasped the point: technology will just improve the speed of processors, and the size and access speed of storage, such that such considerations become irrelevant. Which I have to accept, though I hate. it already has. |
#22
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
In article , Mayayana
wrote: | No, you'll rarely hear me say that, as I come from the bygone era (my | first computer had 1K of memory; before that, the first one I worked on | had 16 memory locations). I will _sometimes_ concede that view when | discussion of time versus resources comes up, but given the choice and | time, I'll go for saving space where practicable. (Actually, more in MP3 | files than images; my eyesight, touch wood, has not deteriorated with | age other than the ability to close-focus, but my hearing _has_ lost | top, and/or I haven't had speakers capable of great top for some time.) | I wish I could switch with you. I don't listen to music in general and usually keep the audio turned off on my computer, but my eyesight is getting worse. I recently mounted my monitor on a drawer slide because I was leaning forward so much it was hurting my neck. now I just sit down and pull the monitor toward me... So I can't lean forward. Though I'm not sure what the radiation from that close display might be doing to my eyes. you aren't actually still using a crt, are you?? get an lcd asap. even a not very good one will be sharper. unfortunately, your winxp systems don't support hi-dpi displays. | (I remember using a Sony camera at work, that had a floppy drive built | in - and you could get several pictures on, of acceptable quality! [That | camera also had something I've never seen before or since: the ability | to use ambient light to backlight the display.]) Wow. 1.44 MB? They must have been small images. But I suppose they were also 256 colors? the cameras were *horribly* slow and shot vga to 1mp jpegs. they were absolute junk. later versions used mini-cds, even worse. https://en.wikipedia.org/wiki/Sony_M...ameras_with_st orage_on_3.5"_floppy_disk |
#23
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
In article , Mayayana
wrote: I have limited experience with photography, but I have got into RAW images. Better cameras seem to offer TIF format for images. very few cameras offer tiff, mostly because it's a complete waste. The best offer RAW. most cameras now offer raw, including iphones and even some compact point & shoots. the cheapest cameras generally don't, mainly because the demographic who buys cheap cameras aren't interested in a raw workflow. Very interesting stuff. It somehow records the sensor data rather than pixels. So you can push and pull the data to what you need before reducing it to pixels. The first time I tried it, I took a picture of a cyclamen in a dimly lit room. I was able to pull out acurate green and magenta hues color in RAW. If it had been JPG or TIF I would have only been able to get brighter pinkish greys instead of magenta. technically, it's sensels (sensor element) but most people call it pixels. it's the same number either way. the distinction is not important. |
#24
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
wrote:
Looking yourself into a single crop ratio is volunteering into silly dogma! The goal is a simple to use tool on Windows that has a GUI that is easier to use than is the slow and cumbersome slide-under-the-bridge aspect ratio GUI of Microsoft Photos. All that is needed is a simple crop, that has a button to restrict it to a given aspect ratio. The Gimp, never an easy to use tool, for example, has an aspect ratio tool. http://www.shallowsky.com/blog/2009/Feb/05/ https://w0.dk/~chlor/www/schou.dk/li...-aspect-ratio/ http://helperthisis146.weebly.com/bl...nload-programs But the goal is a simpler to use Windows free aspect ratio crop, at least simpler (and faster) than Microsoft Photos or The Gimp. |
#25
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
"J. P. Gilliver (John)" wrote | recently mounted my monitor on a drawer slide because | I was leaning forward so much it was hurting my neck. | now I just sit down and pull the monitor toward me... | So I can't lean forward. Though I'm not sure what | the radiation from that close display might be doing to | my eyes. | | CRT or LCD? LCD. Like TVs, they have threaded holes on the back to accomodate mounting hardware. So I made a drawer of sorts, then mounted that with steel drawer slides under a shelf over my desk, also taking off the base. So it's right in front of me and can slide in about a 2' range. I wouldn't want to try that with CRT. |
#26
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
On Sun, 18 Feb 2018 11:05:37 +0000, J. P. Gilliver (John) wrote:
IMO, BMP should only be used when a software doesn't support a better image format. How it stores 24bpp image pixels is unacceptably wasteful. In what way - does it use two 16-bit words, or something? Or do you just mean it doesn't do any (even lossless) data-compression? I meant, it stores 24bpp images pixels in a DWORD storage. How other pixel formats are stored is not wasteful. e.g. - 1bpp: each pixel is stored in a 1-bit storage. i.e. 8 pixels per byte. aka. packed pixels. - 4bpp: each pixel is stored in a 2-bit storage. i.e. 2 pixels per byte. aka. packed pixels. - 8bpp: each pixel is stored in a byte storage. i.e. 1 pixel per byte. - 16bpp: each pixel is stored in a WORD storage. i.e. 1 pixel per 2 bytes. - 32bpp: each pixel is stored in a DWORD storage. i.e. 1 pixel per 4 bytes. 15bpp pixel is also stored in a WORD storage. That's 6.25% waste, but it's an acceptable waste. I know that BMP only stores image pixels uncompressed (lossless). IIRC, support for compressed image pixels such as ZIP, TIFF, JPEG, or others, is not part of the original BMP image format specifications. |
#27
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
On Sat, 17 Feb 2018 23:44:24 -0500, nospam wrote:
nope. a bmp is a representation of an image. Nope. BMP is a container of an image. It's what all other formats decompress to. false. For you who uses Mac OS, that would be true - including *nix OSes. But not for Windows and IBM OS/2. there is also the issue that a given raw format might not be readable at some point in the future, whereas jpeg always will be. I find it difficult to believe that no software in the future will be able to read older image formats - no matter how hard the software developers try to. |
#28
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
On Sat, 17 Feb 2018 22:47:32 -0500, Mayayana wrote:
It depends on the situation. A BMP *is* the image. You can compress it as a TIF if you don't want to use the space, but the format is not wasteful. It's just not compressed. It's what all other formats decompress to. It's what gets displayed onscreen. It's the actual image data of a raster image. Surely you knew that? I know that BMP stores image data uncompressed. But I also know that it stores a 24bpp (RGB) pixel in a DWORD (4 bytes) storage. That's 25% waste. However, I do know that it's for performance purpose. |
#29
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
On Sat, 17 Feb 2018 21:35:36 -0500, nospam wrote:
In article , JJ wrote: This is designed to be simple, quick cropping and resizing, while retaining the best possible image quality when desired. (Crop a JPG and you'll lose some quality, not when it's a lossless or non-destructive crop. That's true for lossless. But the cropping itself is always destructive. no it isn't. You misunderstood. If you crop an image to keep only the left side, the right ride of the image will be gone. Meaning that the crop function itself removes data. Whether there's an undo or redo functionality or not, that an entire different function. bmp is obsolete. In a Mac OS, BMP isn't even the native image container. So, I would be obvious that most, if not all of Mac softwares don't use BMP. In Windows however, not so. BMP is the native image format in that OS. i.e. used by the graphic kernel. |
#30
|
|||
|
|||
Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping
In message , JJ
writes: On Sat, 17 Feb 2018 21:35:36 -0500, nospam wrote: In article , JJ wrote: This is designed to be simple, quick cropping and resizing, while retaining the best possible image quality when desired. (Crop a JPG and you'll lose some quality, not when it's a lossless or non-destructive crop. That's true for lossless. But the cropping itself is always destructive. no it isn't. You misunderstood. If you crop an image to keep only the left side, the right ride of the image will be gone. Meaning that the crop function itself removes data. Whether there's an undo or redo functionality or not, that an entire different function. And you misunderstood our response. _Of course_ cropping discards information - but it was information you didn't want! But also, when you re-save a JPG image after doing anything to it, the lossy compression is usually re-applied, meaning the information in the _remaining_ part of the image is further degraded. Some of us were just pointing out that there is available "lossless JPEG cropping". which achieves a crop _without_ further degradation of the kept part of the image. bmp is obsolete. In a Mac OS, BMP isn't even the native image container. So, I would be obvious that most, if not all of Mac softwares don't use BMP. In Windows however, not so. BMP is the native image format in that OS. i.e. used by the graphic kernel. The information in the graphics RAM while a picture is on screen - whatever the OS - is going to be raw image data, regardless of how it was saved to or loaded from disc. (What _is_ the "native" format for Macs then?) -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf "This is a one line proof... if we start sufficiently far to the left." [Cambridge University Math Dept.] |
Thread Tools | |
Display Modes | Rate This Thread |
|
|