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Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping



 
 
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  #1  
Old February 18th 18, 01:00 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
ultred ragnusen
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Posts: 248
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

Do you know of Windows freeware that has the option to easily lock in a 3:2
or 4:3 aspect ratio for cropping?

I often create DIYs where it's nice to keep the cropped close photos at a
standard aspect ratio of what most smartphones use, which seems to be 4:3,
or to that of most 35mm cameras which seems to be 3:2 aspect ratio
https://photo.stackexchange.com/ques...n-aspect-ratio

I generally crop in Irfanview because it's so very fast & super easy
(click, click, crop), but there is no way to lock the aspect ratio for that
crop to 4:3 in Irfanview, nor in Pinta, MS Paint, or Paint 3D freeware.

Microsoft Photos has an aspect ratio lock, but it's not easy to use as the
image is blacked out except for the crop area, where you slide the
underlying image about to crop.
http://wetakepic.com/images/2018/02/...ard0131bb4.jpg

Do you know of Windows freeware that has the option to easily lock in a 3:2
or 4:3 aspect ratio for cropping?
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  #2  
Old February 18th 18, 02:07 AM posted to alt.windows7.general
Monty
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Posts: 598
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

On Sat, 17 Feb 2018 16:00:56 -0800, ultred ragnusen
wrote:

Do you know of Windows freeware that has the option to easily lock in a 3:2
or 4:3 aspect ratio for cropping?

You could try FastStone Image Viewer. In the Edit utilities, there is
an option called "Crop Board" which gives you some cropping choices.

  #3  
Old February 18th 18, 02:44 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
Mayayana
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Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

"ultred ragnusen" wrote

| Do you know of Windows freeware that has the option to easily lock in a
3:2
| or 4:3 aspect ratio for cropping?

This may or may not serve. It's not free, but you can
use it for free if you don't mind a startup nag:

https://www.jsware.net/jsware/pprep.php5

I wrote it mainly for a friend who was taking a lot
of photos and wanted to be able to send them out
for printing at specific ratios, for framing or for
small photo prints of things like 100 vacation
photos. It will batch crop to any ratio, doing an
entire folder full. Of course, you don't always
want to crop the same area, but for large numbers
of images this will do it quickly and easily, and in
most cases the crop will be fine. You can also pick
the orientation. (Crop from center or a specific
corner.) If you're picky about th exact crop area on
every image then you probably want a fullscale
graphic editor.

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, but you can minimize the
loss, or avoid it by saving as BMP.)


  #4  
Old February 18th 18, 02:50 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
nospam
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Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

In article , Mayayana
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.

but you can minimize the
loss, or avoid it by saving as BMP.)


and drastically increase its size.
  #5  
Old February 18th 18, 03:23 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
JJ[_11_]
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Posts: 744
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

On Sat, 17 Feb 2018 20:50:48 -0500, nospam 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.

but you can minimize the
loss, or avoid it by saving as BMP.)


and drastically increase its size.


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.
  #6  
Old February 18th 18, 03:35 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
nospam
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Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

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.

everything lightroom is non-destructive, including cropping. you can
un-crop and/or re-crop at a later time.

in photoshop, uncheck delete cropped pixels:
https://pe-images.s3.amazonaws.com/p...and-straighten
/non-destructive-crop/photoshop-delete-cropped-pixels-uncheck.png

but you can minimize the
loss, or avoid it by saving as BMP.)


and drastically increase its size.


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.


bmp is obsolete.
  #7  
Old February 18th 18, 04:47 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
Mayayana
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Posts: 6,438
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

"JJ" 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.

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?

A BMP is *exactly* that. Aside from something like 22
bytes of header data, it's no more and no less than
the record of the color of each pixel in the image grid
of the image. It's what any graphic editor actually
works with. You open an image, it's converted
to a device independent bitmap, you edit it, then
it's saved out again as whatever. There's no such
thing as editing a TIF, GIF, PNG, JPG, etc. Those are
just storage methods with different pros and cons.
They're all storing a bitmap. (PNG and GIF can also
offer transparency, but it's still a bitmap that's stored.
The transparency is created by data that defines how
the image gets displayed.)

I suppose you could save as PNG, but neither TIF
nor PNG is remarkable compression. JPG only exists
because it has very good compression, it's royalty
free, and it's cross-platform. The quality is poor, but
it doesn't matter so much for web graphics and
photos of trivia sent between iPhones. It's not
a format for storing photos. Similarly with GIF: It's
handy for creating small files and it's cross-platform,
but it's lossy insofar as it reduces an image to 8-bit
color.

I sometimes save to TIF, but mostly I save as BMP
if I expect to work on an image. I have plenty of room
on disk. If ultred is going to print the images it may
not matter much. But if he's going to do further editing
there's no sense working in a lossy format just to save
space. That's why I designed for JPG and BMP -- One
for small-size images where quality isn't critical and
one for serious image editing.


  #8  
Old February 18th 18, 05:44 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
nospam
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Posts: 4,718
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

In article , Mayayana
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.

It depends on the situation. A BMP *is* the image.


nope. a bmp is a representation of an 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.


in other words, wasteful.

It's what all other formats decompress
to.


false.

It's what gets displayed onscreen.


also false.

It's the actual
image data of a raster image. Surely you knew that?


given that it too is false, why would he?




I suppose you could save as PNG, but neither TIF
nor PNG is remarkable compression. JPG only exists
because it has very good compression, it's royalty
free, and it's cross-platform. The quality is poor, but
it doesn't matter so much for web graphics and
photos of trivia sent between iPhones. It's not
a format for storing photos.


nonsense.

a high quality jpeg is visually indistinguishable from an uncompressed
original (easy to prove).

a low quality jpeg looks like crap, but that's an intentional choice
made by the user, not a flaw in the format, and something that is
rarely, if ever done.

jpeg works quite well for storing photos if raw is not an option. 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.

Similarly with GIF: It's
handy for creating small files and it's cross-platform,
but it's lossy insofar as it reduces an image to 8-bit
color.


that part is (mostly) true. 8 bit colour is not an issue if the gif is
a graphic and not necessarily an issue for photos.

gifs are also useful for animations or short video clips. you can find
many of those at https://giphy.com.
  #9  
Old February 18th 18, 07:59 AM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
B. R. 'BeAr' Ederson
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Posts: 8
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

On Sat, 17 Feb 2018 16:00:56 -0800, ultred ragnusen wrote:

Do you know of Windows freeware that has the option to easily lock in a 3:2
or 4:3 aspect ratio for cropping?

[...]
I generally crop in Irfanview because it's so very fast & super easy
(click, click, crop), but there is no way to lock the aspect ratio for that
crop to 4:3 in Irfanview, nor in Pinta, MS Paint, or Paint 3D freeware.


In Irfanview:
# Create a pre-selection for your crop by Click&Drag with your mouse.
(Be sure, the upper left corner starts on the correct position.)
# Press Shift+c to get the CustomCrop dialog.
# Adjust the Crop to 3:2 ratio (or whatever ratio you like) and click
the button SaveAndDrawOnImage
# Fine-tune the extent of your crop by dragging the borders of the crop
with your mouse while *keeping the Alt key pressed*.
# If need be: Re-position the crop area by dragging it with the *right*
mouse button.

HTH.
BeAr
F'Up set to acf.
--
================================================== =========================
= What do you mean with: "Perfection is always an illusion"? =
================================================== =============--(Oops!)===
  #10  
Old February 18th 18, 12:05 PM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
J. P. Gilliver (John)[_4_]
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Posts: 2,679
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

In message , JJ
writes:
On Sat, 17 Feb 2018 20:50:48 -0500, nospam 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.


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.

but you can minimize the
loss, or avoid it by saving as BMP.)


and drastically increase its size.


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?
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

If liberty means anything at all, it means the right to tell people what they
don't want to hear. - Preface to "Animal Farm"
  #11  
Old February 18th 18, 12:15 PM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
J. P. Gilliver (John)[_4_]
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Posts: 2,679
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

In message , Mayayana
writes:
[]
a format for storing photos. Similarly with GIF: It's
handy for creating small files and it's cross-platform,
but it's lossy insofar as it reduces an image to 8-bit
color.

[]
Not quite: it reduces it to 8-bit _storage_, but it does that by using a
palette. I think the palette entries are at least 16-bit. Basically, it
reduce an image to 256 _colours_, but they're not the _same_ 256 for any
given image: a picture of a sunset, for example, will have a lot of
oranges and reds. And once the reduction has been done, there's no
_further_ compression (though some image editors - like, unfortunately,
IrfanView, which I think is great in most respects - tend to operate in
maximum-colours mode, so edit actions in them _do_ cause degradation
when resaved in GIF. But that's not the format's "fault"; if the editors
could be constrained to work in 256-colour mode, there'd be no loss).
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

If liberty means anything at all, it means the right to tell people what they
don't want to hear. - Preface to "Animal Farm"
  #12  
Old February 18th 18, 03:11 PM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
Mayayana
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Posts: 6,438
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

"J. P. Gilliver (John)" wrote

| a format for storing photos. Similarly with GIF: It's
| handy for creating small files and it's cross-platform,
| but it's lossy insofar as it reduces an image to 8-bit
| color.
| []
| Not quite: it reduces it to 8-bit _storage_, but it does that by using a
| palette. I think the palette entries are at least 16-bit. Basically, it
| reduce an image to 256 _colours_, but they're not the _same_ 256 for any
| given image: a picture of a sunset, for example, will have a lot of
| oranges and reds.

I wouldn't argue with that. But it's still reduced to a
max of 256 colors. It's best for logos, cartoons,
simple images. A sunset will dither. (Remember the
old days on Windows monitors? If you used a sunset
desktop photo you would have had stripes.)

| And once the reduction has been done, there's no
| _further_ compression

As I understand it there is, but it's not lossy. It's
a formulaic system that will record things like "43
pixels of color #18" as a data record, rather than
using 43 * 3 bytes to record 43 pixels. It's very
efficient in that context because repeating pixels are
the norm.

(though some image editors - like, unfortunately,
| IrfanView, which I think is great in most respects - tend to operate in
| maximum-colours mode, so edit actions in them _do_ cause degradation
| when resaved in GIF. But that's not the format's "fault"; if the editors
| could be constrained to work in 256-colour mode, there'd be no loss).

That's just not true. Few 24-bit images use only
256 colors. Try this one:
https://www.jsware.net/Files2/sunsetMV.jpg

IrfanView says there are 100,627 unique colors there.
If I reduce to 256 colors in PSP I get something
like a comic book image, where Superman is in 3
colors.
There are 3 reduction routines down to 256 colors
and the effect varies with each, but all drop out a
tremendous amount of data. If I save as GIF from
PSP I get a pointilistic image. PSP16 does a slightly
smoother job of it than PSP5, but both end up
looking like a print from an old printer. And that
image started as a low quality JPG that had already
been resaved at least twice, so it wasn't a great
picture to begin with. It had already dumped a
lot of the richness. The degradation from the original
would have been heartbreaking to see.

To me that's a great example of the role of JPG
and GIF: Great for onscreen images that need to
be small and that need to be accessible across
platforms. I use GIFs a lot for diagrams. But they're
not good for much else. It would be crazy to store
photos as GIF in order to save space.

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
to saving large images for a good reason, those
same people think it's crazy: "Takes up WAY too much
space!"

I suspect most people who feel that way are taking
loads of pictures with their phone. They just want
2,000 vacation photos to fit on disk. They have no
intention of doing any involved editing or printing of
those images, or even going through to dump the
bad ones, so they're happy with downgraded JPGs.



  #13  
Old February 18th 18, 03:41 PM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
J. P. Gilliver (John)[_4_]
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Posts: 2,679
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

In message , Mayayana
writes:
"J. P. Gilliver (John)" wrote

| a format for storing photos. Similarly with GIF: It's
| handy for creating small files and it's cross-platform,
| but it's lossy insofar as it reduces an image to 8-bit
| color.
| []
| Not quite: it reduces it to 8-bit _storage_, but it does that by using a
| palette. I think the palette entries are at least 16-bit. Basically, it
| reduce an image to 256 _colours_, but they're not the _same_ 256 for any
| given image: a picture of a sunset, for example, will have a lot of
| oranges and reds.

I wouldn't argue with that. But it's still reduced to a
max of 256 colors. It's best for logos, cartoons,
simple images. A sunset will dither. (Remember the
old days on Windows monitors? If you used a sunset
desktop photo you would have had stripes.)


Yes, I had such a monitor (well, laptop).

| And once the reduction has been done, there's no
| _further_ compression

As I understand it there is, but it's not lossy. It's
a formulaic system that will record things like "43
pixels of color #18" as a data record, rather than
using 43 * 3 bytes to record 43 pixels. It's very
efficient in that context because repeating pixels are
the norm.


My bad - I meant loss, not compression.

(though some image editors - like, unfortunately,
| IrfanView, which I think is great in most respects - tend to operate in
| maximum-colours mode, so edit actions in them _do_ cause degradation
| when resaved in GIF. But that's not the format's "fault"; if the editors
| could be constrained to work in 256-colour mode, there'd be no loss).

That's just not true. Few 24-bit images use only
256 colors. Try this one:
https://www.jsware.net/Files2/sunsetMV.jpg


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. The sort of things that _do_ result in
number-of-colours increase include blurring, including resizing
(especially down).

IrfanView says there are 100,627 unique colors there.
If I reduce to 256 colors in PSP I get something
like a comic book image, where Superman is in 3
colors.


Agreed. (Though it's subtle: I didn't notice it at first.)

There are 3 reduction routines down to 256 colors
and the effect varies with each, but all drop out a
tremendous amount of data. If I save as GIF from
PSP I get a pointilistic image. PSP16 does a slightly
smoother job of it than PSP5, but both end up
looking like a print from an old printer. And that
image started as a low quality JPG that had already
been resaved at least twice, so it wasn't a great
picture to begin with. It had already dumped a
lot of the richness. The degradation from the original
would have been heartbreaking to see.

To me that's a great example of the role of JPG
and GIF: Great for onscreen images that need to
be small and that need to be accessible across
platforms. I use GIFs a lot for diagrams. But they're
not good for much else. It would be crazy to store
photos as GIF in order to save space.


Agreed (though there are _some_ images that _don't_ lose a lot: mainly
ones without gradual shading).

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.)

to saving large images for a good reason, those
same people think it's crazy: "Takes up WAY too much
space!"

I suspect most people who feel that way are taking
loads of pictures with their phone. They just want
2,000 vacation photos to fit on disk. They have no
intention of doing any involved editing or printing of
those images, or even going through to dump the
bad ones, so they're happy with downgraded JPGs.

My 'phone - a cheap one (a DooGee) - has, IIRR, a 6M camera. It takes
pictures I consider considerably inferior to those I take with my 3M
Fuji with a reasonable lens - which I usually have set to 1M size (JPEG
that is).

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?

(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.])
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

If it's not on fire, it's a software problem.
  #14  
Old February 18th 18, 03:46 PM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
Mayayana
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Posts: 6,438
Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

"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.

Nospam was just arguing, splitting hairs. It's
really all he does.

| 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?

It has no compression. It's very straightforward.
In general a BMP will be a 24-bit, uncompressed
image. (There are other options, but they're no
longer used as far as I know.) The header looks
like so:
-----------------------------------------
BITMAPFILEHEADER '14 bytes
bfType As Integer (file "magic": "BM")
bfSize As Long
bfReserved1 As Integer
bfReserved2 As Integer
bfOffBits As Long (offset to start of image)

BITMAPINFOHEADER '40 bytes
biSize As Long
biWidth As Long
biHeight As Long
biPlanes As Integer
biBitCount As Integer
biCompression As Long
biSizeImage As Long
biXPelsPerMeter As Long
biYPelsPerMeter As Long
biClrUsed As Long
biClrImportant As Long

----------------------------------------
So, 54 bytes for the header. Following that are
the bytes that represent pixels. The header is just
enough to interpret the image data. So bytes 55-58
will be the first pixel, and so on:
55 56 57 58 59 60 61 62 63 (byte numbers)
00 00 FF 00 00 FF 00 00 FF (3 red pixels, using big endian
notation. Blue is in the high byte. Green is in the middle.)

That's what all raster images are. Pixel grids. Bitmaps.
No raster image format stores anything different. They
just store it in different ways, with varying degrees
of damage to the image. JPG degrades the image to make
it compress better, with less color variety. GIF reduces
to 256 colors and compresses that. (256 colors requires
an embedded color table, which takes up extra space,
but then each pixel can be stored as a single byte.)
I don't know how PNG works but I'm guessing it's
basically a BMP in a ZIP, with the addition of alpha
channel data (transparency) requiring 4 bytes per pixel.
(GIF, by contrast, stores transparency data by indentifying
one specific color that's not to be painted onscreen.)
TIF, likewise, is basically a BMP in a ZIP. (Though a ZIP
can often shrink a BMP by 90%, while a TIF seems to only
manage about 50%. I don't know why.)

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.
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.


  #15  
Old February 18th 18, 04:12 PM posted to rec.photo.digital,alt.comp.freeware,alt.windows7.general
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Default Windows freeware to lock in a 3: or 4:3 aspect ratio for cropping

In article , Mayayana
wrote:

That's what all raster images are. Pixel grids. Bitmaps.
No raster image format stores anything different. They
just store it in different ways, with varying degrees
of damage to the image.


there is no damage.

JPG degrades the image to make
it compress better, with less color variety.


it's entirely up to the user what the jpeg quality/compression level
is, and at its highest quality, a jpeg is indistinguishable from the
original. this is very easy to demonstrate, should you not believe it.

GIF reduces
to 256 colors and compresses that. (256 colors requires
an embedded color table, which takes up extra space,
but then each pixel can be stored as a single byte.)


a colour table takes up very little space.

I don't know how PNG works


clearly.

but I'm guessing it's
basically a BMP in a ZIP, with the addition of alpha
channel data (transparency) requiring 4 bytes per pixel.


nope.
https://en.wikipedia.org/wiki/Portable_Network_Graphics

(GIF, by contrast, stores transparency data by indentifying
one specific color that's not to be painted onscreen.)


true, and primitive.

TIF, likewise, is basically a BMP in a ZIP.


nope.
https://en.wikipedia.org/wiki/TIFF

(Though a ZIP
can often shrink a BMP by 90%,


bull****.

simple logos with large areas of solid colours might shrink that much,
but certainly not with photos. logos would be better served with a gif
or png, not a zipped bmp.

while a TIF seems to only
manage about 50%. I don't know why.)


yep. you sure don't.

They're all just ways to store a BMP. None of those
image formats means anything until the BMP is extracted.


wrong.

One can't render a JPG onscreen any more than the words
of a ZIPped Word DOC can be read from the ZIP bytes.
It has to be decompressed to get the BMP.


decompressed, yes, but no 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.


that part is mostly true. it's more complex than that, but i'll spare
you the details.

It's all just math operations on 3-byte RGB pixels stored
as grids in a BMP.


what you *refuse* to understand is that it doesn't have to be (and
normally is *not*) a bmp.

also, 3 bytes is horribly outdated. these days, it's two bytes per
component or it's a floating point value, with each pixel often having
more than 3 components (rgba, cmyk, hexachrome, etc.)

In other words, the idea that BMP is outdated is a
misunderstanding of what raster images are.


any misunderstanding is entirely with you.

bmp is obsolete. period.
 




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