Last update: 05/10/00

The Frequently Asked Questions (FAQ)

If you have a question on VISION, look at this page. The answer is perhaps here! If not, check out the bugs page !

Q01 When I load a 16 or 256 colors omage, the associated palette seems to be "exploded".
A VISION automatically reserves some colors in a palette in order to let you see menus (if the palette specifies that text and background colors are identical, you won't see anything!). To display the good palette, use the TAB key which will commute between the real palette and the protected one.
Q02 On some images, it appears a white column on the right
A It is on purpose: VISION must align images width on multiples of 16 pixels (due to the ATARI bitplanes). As most of the images are 16 pixels width aligned, VISION uses this and only consider such images by eventually adding some pixels on each line. It also allows faster computations.
Q03 I can't understand why GIF loading is slower than LZW compressed TIFF loading as they use the same compression algorithm!
A Even if it is the 'same' algorithm TIFF is smarter than GIF. First, the order of bits in a LZW TIFF code allows to use some special 68030 bit field instructions. Furthermore, the way the pixels are stored allows another optimisation when converting to ATARI bitplanes. This explains why TIFF can be 200 or 300% faster than GIF for the same compression ratio. Conclusion: use TIFF format instead of GIF!
Q04 When I load a 256 or less colors image, it's unreconizable! And for a True color image, colors are very strange! What's the problem?
A You are probably using a specific graphic card or an ST Emulator. First of all, check the 'Use standard VDI format' box in the Preferences. Then if you are in True Color, click on this button and then 'Detect' and 'OK'. Don't forget to save your preferences when returning to the main Preferences window.

Notes:

  • On a classic ATARI (except HADES, MEDUSA or TT with a graphic card...), you haven't to do this because it will slow down the loadings and will require more memory.
  • Version 3.0c handles 65K True Color mode
Q05 On my HADES, VISION doesn't work in true Color 24 bits and 65K! (version < 3.0c)
A Yes, sorry...In 65K, VISION should work fine soon. But in 24 bits, I have no possibility to test it so no update soon... In True Color modes, you have to choose only 32K or 32 bits in order to use VISION 3.0b! Version 3.0c works fine in 65K.
Q06 Where is the documentation?
A Well... For the French doc, I'm going to make one in HTML format (On Line readable and downloadable). Not for today, it's very long to do! I prefer not to release a paper document because it is most expensive. For the English doc, I must have a least some english users...

Here it is! And in English...
Q07 A little trick for us to wait?
A Use the right mouse button: on the tool bar or the zoom window, it allows parameters and on an image it displays a menu which includes some of the most useful commands
Q08 Why do I haven't iconification on Magic as I have it under TOS 4.92?
A Because of a stupid test which will be removed on the next version (3.0c)...
Q09 Why a True Color image is displayed in grey levels in 256 colors modes?
A Because this is the fastest method to do dithering! I have some ideas to convert True Color to 256 colors but let me some months to think about it ...
Q10 VISION has crashed when loading an image!
A Send me the image file!
Q11 When loading an image, I have a message saying something like this option of this format is not handled
A Most of image formats allows some options (such as interleaved lines, compressions, RGB planes interleaved or not...), no software can handle all of these options (just try to find images of all these options allows, good luck!). So VISION handles some variants and not others. These options are not handled by VISION:

GIF

 TIFF TARGA

BMP

JPEG

Interleaved(*) / Transparency / Animation

 JPEG Compression RLE Compression

RLE Compression

Progressive(*)

(*) Interleaved (GIF) and Progressive (JPEG) variants are handled by VISION only with version 3.5 or better

This seems to be masochism but believe me: the TIFF VISION loader can handle many of the TIFF options!
Q12 Parameters like line width & type, dot type are not restored when I start VISION again, why?
A Is seems not very important to me, but I will do this in VISION.INI, this will make Hallvard happier!
Q13 Sometimes VISION displays an error message at start such as "VMSG.RSC not found, check the VISION.INI file" or "the specified file is not found"
A VISION can't find its VISION.INI or the folders specified in VISION.INI are wrong. The problem is that there are different ways to start VISION:
  1. From its icon on the desktop or in its folder: VISION.INI is wrong, delete it, VISION will regenerate it at next start
  2. You drag'n'dropped a file to VISION's icon on desktop or folder: check that the application VISION is installed as follows with GEM: Folder: Application and Parameter: Folder in the desktop menu
  3. You associated a file extension to VISION: same as 2.
Q14 When I try to filter an image, the progress window appears but nothing happens!
A Check if you haven't validate the 'Use DSP' option in the preferences. If so, VISION is waiting for data from the DSP, which can't be done if you haven't a FALCON...
Q15 What are the limitations of the catalogue file?
A Good question! In fact, the catalogue file size is limited by the maximum file size that the Operating System (TOS, Magic,...). Here are also these limitations:
  • The number of images can't exceed 2^32 - 1 (if you have reached this limit, this means that you have all Internet on your hard disk!)
  • The number of categories is limited by 32 (each image can have up to 3 categories)
  • There was a bug in version 2.5 which crashed the catalogue file when exceeding 8 Mb. This bug has been fixed for version 3.0a (in fact, it appears that this is a bug of the C function fseek)
  • Each image in the catalogue needs 14 bytes of memory (the bitmap icon is only loaded at display time). If you have checked the index saving function, this file is loaded when you open the catalogue

In order to show you an example, I realized an catalogue of more than 3000 images and the resulting catalogue file is about 30 Mb...
Q16 VISION crashes at startup under Magic on a PPC Macintosh
A The problem is due to a the "C" library Stdlib which fails at the detection of the co-processor chip on PPC engines. You must apply FPUPATCH in order to fix this. Note that versions 3.5 and better fix this problem without this patch.