OT: .BMP or .JPG?

[Man at B&Q]

You seem to be the only one who understands that TIFF is not an image format but an image file format that specifies the container format for various lossy or lossless image formats.

MBQ

[dennis]

.bmp could result in getting a windows paint file. That would only be 256 colours and you don't want that. Tiff is a standard format that any photo editor could take.

[dennis]

Would you care to name which application produces lossy tiff files?

[Anna Kettle]

Oh lovely! Thankyou everyone for your comments

I shall ask for TIFF format using the LZW compression option and tell him that if it takes more disks than usual that he should charge me for them

More of a clue? Maybe, but I expect he knows how to operate the machine. If I can do the thinking part, then £16 for 100 slides sounds like a bargain to me

Anna

[Man at B&Q]

[e-mail]...

You referred to TIF as "uncompressed". What would be the advantage of uncompressed against similarly uncompressed bitmap of equal colour depth?

MBQ

[Man at B&Q]

[e-mail]...

No, I don't need to, because I understand that TIFF is a file format, not an image format. As such, a TIFF file can be a container for a lossy jpeg image.

So the answer is that any image handling applpication has the potential to produce "lossy tiff files".

MBQ

[Jules]

Normally LZW-compressed TIFFs, or maybe PNG. BMP's just a little too "windowsy" for my tastes. Don't keep them on CD, either - transfer to something more reliable as soon as you can (I'd even question ever accepting them on CD in the first place, actually).

cheers

Jules

[george [dicegeorge]]

But scanning at what resolution?

at least 300 dots per inch, if its a normal size photo, for printing normalish size, but what do you want them for? what size are they?

if for the front cover of a glossy magazine then more dots per inch.

It's easy to resize the image smaller (less pixels) for web etc, but i dont believe in resizing it to more pixels as being any good.

if there's a part of the photo you want to zoom into then maybe get it scanned at 600dpi.

or buy a scanner with a slide attachment, less than £100 in pc world years ago for my epson perfection 3490 photo and D I Y !

its the processing when youve got a raw scan that takes time, auto levels is step one, then curves...

[g] [g]

[Richard Russell]

Did you not read my reply? I explained that BMP describes a family of formats, most of which undoubtedly are inferior to JPG.

Richard.

[Richard Russell]

The potential advantages of TIFF over BMP are (1) that TIFF can use a greater contrast range (e.g. 16-bits, giving 48-bits RGB) and (2) that TIFF can use lossless compression, resulting in a smaller file.

Correct, and *exactly the same* is true of BMP. In fact it's even possible to store a JPG image in a BMP wrapper (set the biCompression field of the BITMAPINFOHEADER to BI_JPEG) although not many BMP viewers will understand such a file.

Richard.

[Anna Kettle]

3300dpi

I want to use them for Powerpoint displays

I dont think they would let me loose on the front cover, but it would be handy if they were good enough for putting in an article

lost me there

Anna

[dennis]

messagenews: [e-mail]...

OK if you want to be pedantic then I will point out that .BMP files are also a container and can be just as lossy if someone wants to write an application that saves such a file.

The fact that nobody has written such an application is just as relevant as the fact you know of no application that writes lossy TIFF files.

So unless you have a common application that does write lossy TIFF files I will continue to refer to their common attributes as will the rest of users.

Oh I almost forgot, do create file input filters for all the other programs so something can actually read your lossy TIFFs as write once read never files are about as useful as /dev/null.

[george [dicegeorge]]

the first stage is to crop, is he going to send you raw uncropped images, or is he to crop them (may cut too much off) and adjust colours etc.

I would think for powerpoint you need a lot less pixels than for printing, i suggest you get the photoshop wow book, or similar, and learn about pixels, resolution etc...'

scanning at 3300dpi ?? seems very high- or are you scanning from negatives?

The higher res you scan at the bigger better file you get with more pixels which you can store on a dvd or cd and sample down for web pictures, keeping the highres original just in case you get a magazine wanting high res pics.

you cant go from low res to high res, low res jpg are like cassette tapes and mp3s, high res tif are like CDs.

[g]

[g]

[Mathew J. Newton]

Not really. For typical photographs the compression capability of PNG is such that you'd end up with much bigger file sizes with hardly any discernible improvement in image quality.

Mathew

[geoff]

In message , Anna Kettle writes

Most places sell DVDs for a tenner for 50 or thereabouts

Lets face it you can buy a half decent scanner for under £100 nowadays

[Tim Watts]

george [dicegeorge] wibbled on Tuesday 26 January 2010 19:59

She said slides, so effectively same.

>

[Andy Champ]

Decent writeable CDs should be no problem. Good for years, never mind the trip home from the shop! And after all, if she can't read one of the images she just takes the original back next week.

Anna,

Keep the originals. Writeable CDs have a lifetime in years. Not decades.

Andy

[John Rumm]

messagenews: [e-mail]...

But then it would no longer follow the BMP standard.

TIFF on the other hand allows a number of encapsulations to apply to its contents - and already includes a mechanism to indicate to an application what follows and how to interpret it. The formats supported include JPEG, vector graphics, clipping paths, alpha channels and Lossless images. It also supports all the common colour spaces as well. They can also specify no compression, RLE, Huffman, and LZW compression. They also include support to contain multiple pages.

Have a look at the proper spec. JPEG starts on about page 95:

The fact that nobody has written such an application is just as relevant

Some DTP apps can generate TIFFs with JPEG content images as do a number of HTML to TIFF rendering tools. IIRC even the venerable old Art Department Pro on the Amiga had a multitude of similar TIFF generation options.

[John Rumm]

Assuming we are scanning slides/film directly then that is fine.

(needless to say image scanning is a deep subject, and there are far more variables than just raw resolution to play with that will have a big effect on the quality of a scan)

This is a fairly non critical application and can use far lower resolution images generally.

Some editors are still sniffy about letting 35mm sourced material on to a front cover! (insisting on medium format film, drum scanners, and

200+MB image files etc)

Basically if you have a very large image, you may find yourself spending some time hacking it about into a format appropriate for the use each time. (curves and levels etc refers to photoshop operations for manipulating contrast, brightness etc of images in clever ways).

So a disk full of hi res scans is nice to have, however you may want to produce a folder of copies at much lower resolution for use in "on screen" type applications like web sites, powerpointless presentations etc. Reserve the higher res stuff for ODFs designed for printing.

[george [dicegeorge]]

I beleive that external hard drives keep data far longer than CD-Rs, decades, am I right? [g]