Jump to content

Archived

This topic is now archived and is closed to further replies.

RiverCocytus

Rendering issue: Jpeg compression

12 posts in this topic Last Reply

Recommended Posts

  • Original Poster
  • When rendering my latest map, I sought to create very shallow rivers, to allow for more interesting use of the water. However, I ran into a severe problem- jpeg compression would destroy my 9-pixel wide streams.

    Basically, jpeg compression is made to handle photographs, in which case artifacts of the compression mean very little. But in a topographic map, where 1 pixel of difference is meaningful, jpeg compression artifacts can destroy small differences in elevation and remove small, narrow and shallow bodies of water, which would look very neat with covered bridges, stone bridges, etc.

    What I'm proposing, is that since the game itself does accept bitmap images, that the site should as well. My latest map 'Lake Lachdanan' features some details that I only managed by using The Gimp's maximum jpeg compression option '100' which is better than either Photoshop or Paint's.

    BMP's are bigger, but that just means that more detailed maps will have to be smaller. That's cool! I would like to see a greatly increased number of highly detailed, smaller maps to build on.

    I'd be willing to donate to the upgrading of simtropolis, but only on the condition that I might see something like this, something to improve the quality of maps.

    Thanks!

    Share this post


    Link to post
    Share on other sites

    Jpeg compression is only part of the problem. The major problem however, is the inherant limitations of the actual rendering engine. Achieving a very good topographic accuracy in a bitmap is indeed possible, but once the map is rendered, its virtually ignored by the rendering process, thereby making hours and hours of meticulous pixel by pixel drawing of a map, a complete waste of time and effort.
    Sim City 4 is a GAME - it is NOT a geographic, topographic, cartographic, dedicated masterpiece program.
    If you wish to create a supremely accurate cartographic representation of an area, there are cartography programs available by mail order. SC4 is not one of them.

    Share this post


    Link to post
    Share on other sites

    Did you try to convert your bitmap data to jpeg with the highest possible quality, ie a compression factor of 1?

    Both Photoshop and Paintshop Pro have this option.

    Share this post


    Link to post
    Share on other sites

    Cogeo
    That still doesn't get round the rendering engine limitations.
    You could have a 100% pixel accurate jpeg and the rendering engine will STILL mess it up !!!
    Its a game for heavens sake - it isn't DESIGNED to be accurate. To achieve accuracy of the kind rivercocytus (and a few others) is trying to get, would add probably 30 or 40 Mb to the game programing; totally unnecessary in a game.

    Share this post


    Link to post
    Share on other sites
  • Original Poster
  • Well, I'm not even getting into the issue of the SC4 engine, its kind of offtopic...

    Obviously it is just a GAME... however it is a simulation, and I am given to the impression that much of what is being done here is to try to make it more realistic, or to at least feel that way.

    Naturally, we are all bestowed with the inalienable right to hold our own opinions about things diverse, but what your or my opinion on the matter is, is frankly immaterial.

    Even with the max quality (12 on photoshop) It still produces compression artifacts. You would not notice it on, say, a map without a height mod. But on the height modded maps, these small 'artifacts' can adversely affect the appearance, and often the function of terrain.

    Really, I just repeated myself.

    This has become a favorite hobby of mine, and I would like to be able to share my more detailed ideas, but it is regrettable that the jpeg format has certain limitations.

    We could go back and forth all day, you'll say, I swear that max quality jpeg won't produce any artifacts And I will say It does too but unless one of us seriously decides to take the other's statements into consideration I'm just wasting bandwidth.

    Maximum quality jpeg almost HAS to produce artifacts-- Unless you can show me technical documents stating otherwise.

    It has become a limitation for me, and I was expressing that to the Simtropolis community. My suggestion is to allow BMP's to be uploaded (same size limit) as well as JPEGs.

    I will say no more until this conversation has advanced to a further state.

    Share this post


    Link to post
    Share on other sites

    With respect rivercocytus, you talk of realism and accuracy and then totally dismiss the fundamental problem, as being off topic !!!
    The problem in producing an accurate map for the GAME of Simcity 4, is the RENDERING ENGINE. It has very little to do with jpegs, compression factors, or bitmaps. The game itself is simply not capable of rendering accurately from ANY format of greyscale image. On the average 4 x 4 large city map, just one pixel would represent an area of perhaps 4 or 5 sq miles, and if there is any great difference in greyscale between 2 or more adjacent pixels, the rendering engine virtually ignores it, or at least radically smooths it out.
    Even on a large scale map, a small hill represented by perhaps 10 pixels, would be flattened, or even totally obliterated. Topographic accuracy, even using a MASSIVE bitmap would be at the very best, reasonably close. But are you expecting the STEX to accept 25 Mb bitmaps ?? It aint gonna happen.

    Share this post


    Link to post
    Share on other sites
  • Original Poster
  • Vandy says:
    CORRECTION: Once you've clicked on the Download Map link, click on the Download Map link once again to display the map. If necessary, click on the size handle in the image. THEN, right-click on the map and save it as a .BMP type. Sorry for the confusion.

    So I could rename it to a .jpg file, upload it, and as long as I am within the 2.5 mb limit, it should work? I might try it for a smaller map.

    Thanks, Vandy! (Although it would have been easier to just respond to this thread.)

    Share this post


    Link to post
    Share on other sites

    umm doesn't one pixel equal 1 6metrer by 16 metre ? if you have a recent version of paintshop pro ot photo shop can't you remove the jpeg artifacts us Jpeg artifact removal? i have done it in paintshop pro i just tok a bit of mucking around to get the right settings

    Share this post


    Link to post
    Share on other sites
    Guest

    Lets see....it's been a very long time since I did terrains for SC4, but I remember this issue. If you want to get elevation data to transfer to SC4 as accurately as possible there are a couple things you must do. 1) Don't use JPG. Doesn't matter what quality settings you use, any compression cause loss of a lot of detail. Zoom in and see what happens to the individual pixels when you go from uncompressed BMP to JPG. They get all messed up. 2) Make sure to use "Nearest Neighbor" transformations in your image editing program when working with the raw data. The bilinear and trilinear transformations cause artifacts at the pixel level similar to JPG compression. Cheers, Matt Fox

    Share this post


    Link to post
    Share on other sites

    The science - with all due respect - is irrelevant ............. the renderer simply is INCAPABLE of transferring intricate details of pixel differences - bitmap, jpeg, whatever, doesnt matter - the RENDERER is the problem

    Share this post


    Link to post
    Share on other sites
  • Original Poster
  • Bah; JH. But thank you, forkboy2: This will be helpful in making less artifacts even in the JPG terrain maps. Adobe by default uses a bilinear transformation, I believe. This is probably some of what was messing up my more delicate terrain features.

    Share this post


    Link to post
    Share on other sites

    Well I wish you luck Rivercocytus, I really do hope you find a way of getting around this problem. As I have said before, like you, I am very frustrated that hours of intricate work with a small painbrush is often obliterated on the render !

    Share this post


    Link to post
    Share on other sites

    • Recently Browsing   0 members

      No registered users viewing this page.

    ×

    Help Keep Simtropolis Online, Open & Free!

    stexcollection-header.png

    Would you be able to help us catch up after a bit of a shortfall?

    We had a small shortfall last month. Your donation today would help us catch up for this month.

    Make a Donation, Get a Gift!

    We need to continue to raise enough money each month to pay for expenses which includes hardware, bandwidth, software licenses, support licenses and other necessary 3rd party costs.

    By way of a "Thank You" gift, we'd like to send you our STEX Collector's DVD. It's some of the best buildings, lots, maps and mods collected for you over the years. Check out the STEX Collections for more info.

    Each donation helps keep Simtropolis online, open and free!

    Thank you for reading and enjoy the site!

    More About STEX Collections