Groups > comp.lang.basic.visual.misc > #2438

Re: VB6 Image Resizer

From	"Mayayana" <mayayana@invalid.nospam>
Newsgroups	comp.lang.basic.visual.misc, microsoft.public.vb.general.discussion
Subject	Re: VB6 Image Resizer
Date	2020-03-30 09:52 -0400
Organization	A noiseless patient Spider
Message-ID	<r5stja$skl$1@dont-email.me> (permalink)
References	(8 earlier) <r5qvsi$u8l$1@dont-email.me> <r5r85g$mc7$1@dont-email.me> <r5r8l8$p8r$1@dont-email.me> <r5rod6$4sr$1@dont-email.me> <r5sm2n$731$1@dont-email.me>

Cross-posted to 2 groups.

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"GS" <gs@v.invalid> wrote

| Thanks for making it as simple as possible; - still, it'll take awhile for 
me
| to digest! At first read I don't see where AspectRatio plays a part; - 
looks
| like I need to specify both width and height. This could be problematic 
where
| original size is not 3x4 or 4x3 AR, requiring lots of calc code. 
(Unfortunately
| most of the pics are NOT either AR) The apps I'm using now auto-adjust
| according to AR; - I need to duplicate that behavior so I only pass 1 
dimension
| based on orientation derived from the original pic! I could be wrong 
though!
|

  Wouldn't that just be a calculation? I didn't
understand your original note about getting ratio,
but I assumed were reducing the largest dimension
to 640. So then it's just arithmetic to get the small
dim as the same ratio.
  smalldim = (bigdim \ 640) x orig small dim

   I haven't looked at this stuff for awhile. I'm
wondering whether the class is really the best
thing. Maybe if I have a chance I'll try a test,
adding the VB Bilinear resize method to the resize
test I linked from online.

   Some time ago we spent a long time dealing
with this. I was looking for the fastest thumbnail
generator. I finally ended up with turbojpeg +
minor resizing.

  The class I have was for my photo editing program.

  I assume you want decent quality. The resize test
I linked is interesting in that respect. It shows that
GDI+ is slightl faster than WIA and much faster than
resizing an image control. But it also shows quality
differences. I have a 12 MB image of maple trees.
GDI+ resizes well but blurs it slightly. VB image control
produces far too much contract, making the leaves look
like bright color dots. WIA is slightly inferior to GDI+.
So GDI+ is best. I expect it's probably also better
than StretchBlt, but I don't know for sure.

  What I also don't know is how the speed and quality
of GDI+ resize compare to the straight VB math code
for bilinear and bicubic in the cImage class. But maybe
I'll try to add that into the test project.

Thread

VB6 Image Resizer GS <gs@v.invalid> - 2020-03-28 00:26 -0400
  Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-28 10:04 -0400
    Re: VB6 Image Resizer Arne Saknussemm <es215.10.wannabet@spamgourmet.com> - 2020-03-28 17:17 +0100
      Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-28 14:12 -0400
      Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-28 14:43 -0400
        Re: VB6 Image Resizer Arne Saknussemm <es215.10.wannabet@spamgourmet.com> - 2020-03-29 15:48 +0200
          Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-29 10:41 -0400
          Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-29 13:30 -0400
            Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-29 13:54 -0400
              Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-29 15:36 -0400
                Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-29 16:19 -0400
                Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-29 18:40 -0400
                Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-29 18:49 -0400
                Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-29 23:17 -0400
                Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 07:44 -0400
                Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-30 09:52 -0400
                Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 12:37 -0400
                Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 13:35 -0400
    Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-28 14:59 -0400
      Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-28 16:39 -0400
        Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-28 17:57 -0400
        Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-28 18:44 -0400
          Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-28 22:49 -0400
            Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-29 13:22 -0400
  Re: VB6 Image Resizer "Peter T" <askmy@email.com> - 2020-03-30 17:29 +0100
    Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 12:34 -0400
      Re: VB6 Image Resizer "Peter T" <askmy@email.com> - 2020-03-31 10:59 +0100
        Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-31 09:43 -0400
        Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-31 12:53 -0400
  Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-30 18:20 -0400
    Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 18:50 -0400
    Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 18:56 -0400
      Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-30 21:24 -0400
        Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 21:30 -0400
          Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-30 22:01 -0400
            Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-30 22:11 -0400
  Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-31 17:41 -0400
    Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-31 17:51 -0400
      Re: VB6 Image Resizer "Mayayana" <mayayana@invalid.nospam> - 2020-03-31 21:08 -0400
        Re: VB6 Image Resizer GS <gs@v.invalid> - 2020-03-31 21:14 -0400

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