BMP vs JPEG

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Eye-level

Banned
Something I discovered the other night playing around with some different file formats is that if I convert a jpeg straight out of the camera to a bitmap I get a running ton more information and a much cleaner crisper image on my monitor or wherever I post an image too.

For example a 2848 X 4288 jpeg image from my camera is a 1.27 MB file...

But...convert said file to a bitmap and all of a sudden it is a 34.9 MB file...and a heck of lot cleaner and crisper and all of the above.

Then if you scale that down to say 1000 X 1500 you get a nice workable around 4 MB file.

Seems to me that is very much like shooting RAW at least in terms of file size...

Any thoughts on this? Anyone work with jpegs converted to bitmaps?
 
BackdoorArts

BackdoorArts

Senior Member
In terms of file size, perhaps. In terms of real light information per pixel, I doubt it. Bitmap files have been around since the first graphics programs, and I'm sure the format has its purpose in terms of producing graphics. But given that I've not once heard anyone mention it in reference to digital photography, I suspect it's the last thing you want to use to manipulate your images.
 
E

Eye-level

Banned
Thanks for replying Jake.

You ought to check it out a bit further...I can't find much on the net about but just as sure as you convert to bmp from jpg all of a sudden there is a ton of data there.

In terms of information per pixel as you mention above I am fairly certain that a RAW file is the only thing that will collect directly what the sensor saw but there has to be a whole lot more to work with on a bmp compared to a jpeg even though the bitmap is derived from the jpeg...I wonder if the bmp is just an uncompressed jpg so to speak?
 
E

Eye-level

Banned
OK a little experiment here...

First pic is a jpeg straight out of the camera no processing other than resizing.
Second pic same jpeg no processing other than conversion to bitmap and resizing.
Both are hosted on the same server same way other than file designation.

Plainly obvious that there is a big difference in the two...so what is going on here?
(Notice how the jpeg is showing more definite stair stepping opposed to the smoother bmp - the smoothness of the bmp is a quality you'd find with a RAW file)

098.JPG


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098.bmp
 
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E

Eye-level

Banned
Thanks for the link...higher resolution and higher image quality...the color is not quite as rich but I can change the bit depth of the pixels...I'm sold no more jpegs for me.

Next I am going to see about the TIFFs...trying to stay away from RAW for now...need to understand this other stuff more completely first.
 
BackdoorArts

BackdoorArts

Senior Member
The reason you get crispness with a BMP is that it's a direct conversion to, well, a bitmap. No compression, no further interpretation. But once you're there, it's a pure graphics file that will let you interpret down fairly easily, but not anywhere else. I've been playing with them since Paint came out on the first Windows machines. It's a basic color to bitmap representation, which is fine for a one time conversion, but after that, IMHO, you're screwed - at least when compared to other formats.

Again, if it wasn't so, somebody with a name in the game would be using it. I'm not budging from RAW, so it matters not to me. I want that information preserved. Otherwise I'd using be using something other than a camera to paint my pictures.
 
E

Eye-level

Banned
I have been playing with them for a long time too and it used to tick me off to no end to have to convert those bmp files...I sure do like them better than jpgs for posting pics to the net now though. I suppose I will have to get used to dealing with RAW files at some point though...as little manipulation as I do it probably wouldn't be that big a deal anyway.
 
R

Rexer John

Senior Member
You can't get more information out of a file than it already contains.
What you can do is sharpen or soften. The image may look to be better than before and different image formats may look slightly different because of compression algorithms but you didn't release any extra information no matter how large the file size is.

On the other hand, an image may look pixelated when it's enlarged. If you resample the image to larger size (number of pixels) you can blend the extra information into the image for a much better final image.
You still didn't get more information out of the original file but you added "smart pixels" in between the originals.

A BMP file saves each pixel as an individual unit of information so the file is huge.
A Jpeg looks for areas of similar pixels and encodes the picture to get a much smaller file size.
You get to chose how much compression you want, more compression = a more blocky image.

If you start with a compressed jpeg image and then turn it into a bitmap resulting in a better image, the better image most likely comes down to a blending of the original jpeg image, removing artifacts prior to the image save.
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Horoscope Fish

Horoscope Fish

Senior Member
When in PS I avoid converting RAW files to standard.jpg's whenever possible. If it's an image worth converting it's converted to .tif since it's an uncompressed format and ideal for printing. If I feel I need to compress the image for some reason I use .jpg optimized. Thankfully every browser under the sun will work with optimized JPG's these days, which has not always been the case. This format also uses slightly better compression and optimized color (hence the name, I suppose). I don't really see any use for .bmp because it really has no advantage over .tif that I'm aware of.
 
BackdoorArts

BackdoorArts

Senior Member
Eye-level said:
I think getting away from file compression is ultimately what I am looking for... :)
Click to expand...

Which begs, no screams the question, "Why the heck don't you want to shoot RAW and be done with it?!" You're going to wind up there eventually. Why not start out with it instead of starting with a compressed file with less information than you could have?! You're making a hell of a lot of additional work for yourself.
 
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