info

[Stan]

Hi all,
on the pages http://muzeum.pre.cz/  you can find no only my lamps (today increased number of lamps), but (in english version)also collections of insulators my friend Frantisek Danek and basic collection of PRE = different electrical devices with Czech electricity history. Stan

[This message has been edited by Stan (edited January 17, 2004).]

[Mónico González]

Hi Stan!

I've seen you have remodelated your website.
It looks cool!

Very interesting the historic researching about the electric power evolution in Prague.
My Sister are insistent to me about to begin with a similar task on the birth and consolidation of Electric generating and distribution systems here in Ciudad Real, but there is a big amount of historical documents and data to search and process.
Perhaps in a few months when I will be a  bit less busy...

Best regards,
M. Gonz?lez
 http://mis-bombillas.webcindario.com

[This message has been edited by M?nico Gonz?lez (edited January 17, 2004).]

[debook]

Just a passing thought.

For Chris, Stan, Monico and James.

It might be a nice idea to integrate our web sites to make a single European site. We can then share notes, help each other on translations etcetera. Also it would make it easier to find a 'Museum' host that would allow the site to be preserved indefinitely.

I have completed my clean up of the VVG poster lamps. A huge effort but fascinating to study these all in such detail. Purely by chance the individual lamp images are virtually life size.

Frank

[Tim]

Hi Frank,

quote:Originally posted by debook:
Also it would make it easier to find a 'Museum' host that would allow the site to be preserved indefinitely.

Can you elaborate on this further for me?  Are you speaking of the ?dot museum? type domains?

Thanks,

------------------
Tim
Kilokat's Antique Light Bulb Site
Mountain Dew Collectibles, Volume I

[Yoshi]

quote:Originally posted by debook:
...Purely by chance the individual lamp images are virtually life size.

I guess I could help optimize them. I know how to make them look the best and yet have a small file size.

[debook]

Tim

No I was not thinking about the .mus domains but long term storage. Most websites only exist as long as the owner is around and most web archives only store text.

I am currently discussing transfer of my glass web-site to a Museum for permanent storage.

My lighting site is fairly limited but does contain previously unpublished information and there is a lot of history still hidden by the different languages used in Europe. I thought it might be a nice project to pool efforts to enable the information to be more widely available and then look for an institution that would host it for the future. Much in the way that this forum provides a means for collectors and others with an interest to duscuss and share their knowledge on individual topics.

My glass site has almost reached the limit of what one person can do in spare time and it has a much more compact subject matter than the history of lighting!

[debook]

Yoshi,

Thanks for the offer, I presume you mean tweaking the jpeg compression ratio to the point where the image is still recognisable?

Currently they are all compressed to what I felt was reasonable, I still have uncompressed bitmaps of all the images. I would prefer to use a wave compression format (Jpeg 2000) but until that is supported as standard in browsers it will deter some vistors.

Ideally I would like to find a way of renoving the background from between the lines on the engravings but have yet to find a tool that can do that without damaging the lines! I cleaned out the surrounding background by hand which took between 20 and 40 minutes per image. On one image, the Cosmos leaflet, I used a tool that did remove the background from inside the engravings but it also resulted in the loss of some engraving.

The problem is that the tools generally rely on contrast to select for removal and finding a figure that works across an irregular contrast has proven unworkable. If you know of another tool let me know. I mostly use Corel PhotoPaint 8.

[Mónico González]

Hi everybody!

About image compression ratio, Debook are right.
The most reasonable thing is to take and store all pictures at the largest size it  can be done because the CD is today almost a "virtually infinite" media to allow a massive filing of images at uncompressed mode (logically if one are ready to store more and more CD's at home each time some pictures could be archived, hi!)
After that, everyone can select its own system (and ratio) to compress the files to conjugate the largest practical size to the picture cannot be too degraded but the smallest available to avoid a excessive downloading time.
I personally prefer to store the files in .BMP (rgb) format that means that the whole bitmap are absolutely uncompressed in any way. (it can be observed when one looks the file size: all the files with the same pixel resolution, are equally sized in bytes).
I strongly recommend to keep such uncompressed "fat" files as "masters" for further manipulations. Please, never erase them!
Afterward the files are downsampled at the required size and stored as .jpg compressed mode, leaving "untouched" the original ones for further uses.
These "miniaturized" versions are the web picture files that will appear at the website along with the text.
In case of limited colour range pictures (16-256 colors in plane-tone draws, buttons, logos, etc.) a rate of 4 to 8 bits per pixel at .GIF files are the adequate choice.
Eventually when one are scanning grey-scale pictures, the number of bits per pixel can be reduced without any visible degradation of the image; but in the case of pure line (black/white) originals, the whole picture could be codified only at ONE bit per pixel, with the subsequent saving in file size.
Best regards,
M. Gonz?lez.
 http://mis-bombillas.webcindario.com

[Yoshi]

Well I was thinking of doing a lot more than just increasing the compression. There are many ways to optimize a jpeg image. When I say optimize, I mean finding the best combination of image quality and file size. It does not necessarily mean reducing the quality of the image (and in most cases it doesn't). It all depends on what's on the image. For example, if you take a picture of a lightbulb with a white towel as the background, you will get a picture much larger in file size than if you had used a white sheet of paper in place of the towel. Think of jpeg as a format that needs to describe an image to work: the more items and color there is in the image, the more text you'd need to write to describe it fully, and so does jpeg. Think of the towel: jpeg needs to describe every single string on the towel. with the blank sheet of paper, it only needs to specify the color. jpeg saves in blocks rather than pixels (which I call "jpeg blocks"). Perhaps you have noticed that some highly compressed images look like a checkerboard? Well, those are the jpeg blocks. They are small on high quality images, and large on low quality images.

As for the "master" files in BMP format, I do not suggest using BMP for large images. There are many other ways to save your original images, all without sacrificing image quality. Try the TIFF format. It is of the same quality as BMP but is significantly smaller in file size. Or you can also use Adobe Photoshop and save the BMPs as jpegs of quality 10. This is the same as saving them in BMP, except that the images will be far smaller. But if you insist on using BMP, at least zip them! They're huge!

Actually, computers use images in BMP format all the time, whether they are saved to disk as bmp or not. The space used in RAM for a BMP image should be the same as with a jpg or gif image of the same dimensions. Formats other than BMP were created mainly to save disk space.

I would need to see the images in order to tell what I can do to optimize them.

You are right, the way the pixels are codified is another way to optimize a digital picture.  


-Yoshi

[debook]

A bit of a delay in reacting, busy times.

I found a way of removing background from images of etchings. Scanning at 2400dpi minimum gives sufficient contrast for lasso tools to work without damaging the engraving lines. The only problem is that this creates a bitmap size of 800Mb for the VVG posters and nearly 2Mb for each bulb. My present PC and Windows ME and Corel software cannot cope with the former and crashes after three or four operations on a single bulb image. I am upgrading so will try things out again and report back.

However, one problem that can still occur, even with all background removed is that the final jpg file size for web can still be larger than with background. In some tests on tiny portions, I discovered that once you get gaps below a certain size the jpg algorithm actually creates larger files than when the background is present.

Incidentally, TIFF is not a compressed image format and will give sizes comparable to BMP when used in its standard format. However, TIFF does support compression and unfortunately can be found with several flavours. Professional packages can use LZW compression but cheaper software usually uses a free compression, also some of the more esoteric professional imaging software used other types of compression to tie users into their software. The tif plug-in for browsers only works with LZW compression or no compression. If you keep TIF for long term make sure that when you upgrade your system/software that you can still access the TIF's!!!!!!!

Using 256 colours is good on space now but storage costs are running downhill so the economy is short-lived. 200dpi screens are not that far off now and these will make low quality images look a lot worse than they do on standard 96dpi screens now. IBM are the only ones currently selling 200 dpi screens now, they are custom made for medical and forensic users and very expensive. But all web site owners should consider being ready to upgrade their images within the next ten years.

[Yoshi]

Well, I have an entirely different view...

If properly saved, there's no way a jpeg image of a bulb without a background can be larger than one with background. The image would need to be of larger dimensions and/or have finer detail than the first one to be larger in file size. If you sharpen an image and then save it as a jpeg, you will notice it will have a larger file size, simply because it now has more detail. This may be the case with your pic without the background? Also, if you open a jpeg, and then you edit it and re-save it as a jpeg then you will end up with an image that looks worse and is larger in file size than if you had used the bmp version of the image to edit it instead.

I save my TIFF images with Paint Shop Pro 7, and they can also be read by MSpaint too, which is included in all Windows systems. They are significantly smaller in file size than their bmp counterparts. For example I have a picture that is 3.51 MB as bmp. As TIFF it is 2.17 MB. That's great for a loss-less image format (no image data is lost, unlike gif and jpeg). But I still think it is much better to use high-quality jpeg than tiff on pictures; I also try to keep a balance between the importance of the image and the disk space it will use. If the image has no specified date of re-use (or it may even never be used again), then why waste hard disk space with huge bitmap versions of it??

I believe scanning at 2400 dpi is completely unnecessary...
When I edit my images, I don't rely completely on automatic tools...

Here's one of my backup high-quality, high-resolution images, please take a look at it:

http://img.2yr.net/IMG_0664.jpg


It is only 87.9 KB in size. I really don't need any more detail than that. A reduced version of this image is being used on the following page:

http://bulbs.2yr.net/green-tipped-mazda.html


Please do not use 256 colors on real pictures, they will be ruined!


-Yoshi