> i need to know the size of an image without reading the whole file. any
> ideas where to start? i assume some p/invoke would be needed :/
> i need this because loading whole images into memory takes lots of time.
> and when you have lets say 300 of them, 6Mpix each it may take ages.

"SharpCoderMP" <csharp_mp@interia.pl.NFSPM> wrote in message
news:%23hA29veLIHA.1208@TK2MSFTNGP05.phx.gbl...
> hi,
> i need to know the size of an image without reading the whole file. any
> ideas where to start? i assume some p/invoke would be needed :/
> i need this because loading whole images into memory takes lots of time.
> and when you have lets say 300 of them, 6Mpix each it may take ages.

> what about shell? explorer is pretty quick when it comes to reading
> image size (and thumbnail). maybe i could use some of the shell32
> features? i've seen great thumbnail image extractor (using shell) on
> vbaccelerator. i thought that there would be some way to use the same
> technique to obtain only image size. unfortunately my knowledge is
> rather limited when it comes to shell programming :/

"SharpCoderMP" <csharp_mp@interia.pl.NFSPM> wrote in message
news:%23fXCrkoLIHA.3852@TK2MSFTNGP06.phx.gbl...
> Michael Phillips, Jr. wrote:
>>> i need to know the size of an image without reading the whole file. any
>>> ideas where to start? i assume some p/invoke would be needed :/
>>> i need this because loading whole images into memory takes lots of time.
>>> and when you have lets say 300 of them, 6Mpix each it may take ages.
>>
>> There are many image formats. The size of the image when loaded will
>> only
>> be known after the image has been decoded.
>>
>> This is especially true for any image that is compressed. Until the
>> decoder
>> finishes the decompression, there is no way to know the size of the
>> image.
> what about shell? explorer is pretty quick when it comes to reading
> image size (and thumbnail). maybe i could use some of the shell32
> features? i've seen great thumbnail image extractor (using shell) on
> vbaccelerator. i thought that there would be some way to use the same
> technique to obtain only image size. unfortunately my knowledge is
> rather limited when it comes to shell programming :/

Michael Phillips, Jr. wrote:
>> i need to know the size of an image without reading the whole file. any
>> ideas where to start? i assume some p/invoke would be needed :/
>> i need this because loading whole images into memory takes lots of time.
>> and when you have lets say 300 of them, 6Mpix each it may take ages.
>
> There are many image formats. The size of the image when loaded will only
> be known after the image has been decoded.
>
> This is especially true for any image that is compressed. Until the decoder
> finishes the decompression, there is no way to know the size of the image.

> now i'm confused. or maybe my original post was confusing :/ the data i
> need is in fact image's width and height. so the question is can it or
> can not be done in some fast way (ie using shell32)?

"SharpCoderMP" <csharp_mp@interia.pl.NFSPM> wrote in message
news:Or%23xFrrLIHA.4948@TK2MSFTNGP02.phx.gbl...
> Michael Phillips, Jr. wrote:
>> The image decoder reads the signature first, then the headers and finally
>> the image itself.
>>
>> The headers will reveal the width and height not the size of the image
>> when
>> decoded.
> now i'm confused. or maybe my original post was confusing :/ the data i
> need is in fact image's width and height. so the question is can it or
> can not be done in some fast way (ie using shell32)?

Michael Phillips, Jr. wrote:
> The image decoder reads the signature first, then the headers and finally
> the image itself.
>
> The headers will reveal the width and height not the size of the image when
> decoded.