-1

I don't know the number of pixels.

7x3.6 meters

Would an image of 127 kilobytes be good enough for an advertisement that size?

Digital Lightcraft
  • 9,060
  • 3
  • 31
  • 69
user54112
  • 15
  • 1
  • 2
  • 10
    I think the general answer will be "HAHAAHAAH!!! err... no" – Digital Lightcraft Jul 21 '16 at 19:05
  • 5
    Is the entire billboard a single solid color? In that case, you've got a significant excess of data. – mattdm Jul 21 '16 at 19:10
  • Even though I offered an answer, I'll point out that this may be straying outside the bounds of what's on topic here. Not every question that deals with pixels is relevant to photography. – Caleb Jul 21 '16 at 19:34
  • Why is 127 KB important? – scottbb Jul 21 '16 at 19:58
  • 2
    Hi user54112 and welcome to Photo.SE. I have voted down your question as it lacks any prior research. Could you please search a bit on this site and on Google, then update your question if you have any further questions. This question is for example related and might help you. – Saaru Lindestøkke Jul 21 '16 at 20:19
  • Is this really a real-world situation? If you are going to proceed with a billboard advert, then find out more about the image you are using! – osullic Jul 21 '16 at 23:10
  • Do you really mean KILO-bytes, i.e. 127,000? – Jim Garrison Jul 22 '16 at 03:48
  • Not to mention that there's no single relationship between filesize and number of pixels. Just imagine an RGBY image with 256-bit color range. – Carl Witthoft Jul 22 '16 at 11:28

5 Answers5

8

Would an image of 127 kilobytes be good enough for an advertisement that size?

You really need to know the dimensions of the target billboard in pixels. It's possible that you've got a highly compressed file that will expand to the right size, but it's also possible that your file will be too small to display nicely. It's also not clear if you mean a conventional billboard where you print the image onto vinyl or some other substrate that's then displayed, or if you're talking about a digital billboard that displays the image using a large LED display. Digital displays seem to have much lower resolution, and they probably don't really need 24-bit color to look good.

So, the best answer really is sort of a non-answer: Ask your billboard service provider for their requirements.

Caleb
  • 31,682
  • 6
  • 65
  • 120
  • Even if you have a low-rez display, you don't want any of the pixels to have a bogus value because of compression artefacts. You're probably fine with a high-quality image of exactly the same rez as the sign, but I'd worry about a high-rez low-quality image unless I checked it carefully against against a high-quality image after downscaling both. – Peter Cordes Jul 21 '16 at 20:29
5

First-off lets assume you are talking an IMAGE, not a vector file. So lets say jpg.

If you work on 50DPI print, you would need an image of aprox 13,780 x 7100px.

which is nearly 98 mega-pixels.

OK so I know what you are thinking - it doesn't NEED to have the full print resolution to be a good billboard print. So lets say we will settle for a printed pixel size of 1mm to be nice and sharp from a distance.

This is 7000 x 3600 = 25 MP

OK so maybe from a few meters away 2mm x 2mm will be acceptable:

3500 x 1800px = 6.3 MP

Now lets save a photo at 3500x1800 to a quality setting that gets it to 127-ish KB:

enter image description here

Surprisingly its NEARLY acceptable, but for gods sake please dont!!!

Digital Lightcraft
  • 9,060
  • 3
  • 31
  • 69
  • 1
    If — and this is unlikely, but, hey — it's compressed with something more modern like JPEG 2000 or JPEG XR, it could be even better.... – mattdm Jul 21 '16 at 19:32
  • Maybe, but now lets start adding text and a logo in there.... ! Additional: given the question, also highly unlikely. – Digital Lightcraft Jul 21 '16 at 19:33
2

See this answer on the graphic design SE. 10 DPI is apparently a normal resolution for something that size. These days they're printed on giant roll-fed inkjet printers, directly onto vinyl.

My recollection of a colleague who did this for a living is that more like 10-100M for the image size would be normal (probably TIFF format so lossless compression to keep the type sharp). If someone else is superimposing the text you can presumably go a lot lower for the photographic image, but ugh.

Community
  • 1
Spehro Pefhany
  • 221
  • 1
  • 4
1

If and only if your advertisement's pixel size is ~2.4cm/pixel (or about 1 in. per pixel, or 1 PPI).

The area of your 7×3.6m billboard is 25.2m². Assuming a 127 KiB file contains only 3 byte-per pixel data (uncompressed, no metadata, image format headers, etc.), that means you are presenting only 42.3×1024 actual pixels. Dividing, that gives you 5.8×10⁻⁴ m²/px. Taking the square root give a pixel dimension of 2.4cm/px, which is pretty close to 1 PPI.

scottbb
  • 32,685
  • 12
  • 104
  • 188
0

Others might poke fun of 127 kilobytes but I would like to give you the benefit of the doubt.

IF you are using a scalable vector file such as .svg, .svgz, .ai, .eps, and others then the kilobytes have no correlation to the finished product as long as the printing software or printing company knows how to work with scalable image formats.

If you have a run-of-the-mill .jpg, .bmp, .gif, .png, and many many more then 127 kilobytes will not be enough to print on a 7x6.3 meter canvas. There is no magic for fixing it either.

I hope this helps.

MonkeyZeus
  • 261
  • 1
  • 8
  • 1
    If you are using a scalable vector file, then this is probably quite off topic. – mattdm Jul 21 '16 at 20:28
  • @mattdm This isn't about me. It's possible that OP is misinformed and has asked this question on the wrong StackExchange site. Just figured I could provide a glimmer of hope for the poor guy. – MonkeyZeus Jul 21 '16 at 20:31
  • Yes, sorry, "you" was addressed to the question asker – mattdm Jul 21 '16 at 20:32