please help with images

[dvst8]

Two questions regarding resizing images:

#1
I need to do some dynamic thumbnailing, basically, just resize a picture and save it on the fly....

Here is what I have so far:

Private Sub Form_Load()

    Image1.Visible = True
    Image1.Stretch = True
    Image1.Picture = LoadPicture("c:\myPic.jpg")     

    widt = Image1.Width
    higt = Image1.Height

    newWidt = 1500
    scaler = widt / higt
    newHigt = CInt(1500 / scaler)

    Image1.Width = newWidt
    Image1.Height = newHigt
        
    SavePicture Image1.Picture, "c:\temp1\test.jpg "

End Sub

This correctly resizes the picture in the window, but does not save it right. I know there has been some posts on this topic before, except I can't seem to get it right...

Using Image I can set Stretch = True and the image stretches correctly, but does not save with new dimensions (I cant do the following line, which is what I would need):

SavePicture Image1.Image, "c:\temp1\test.jpg"

Using PictureBox, I can save the new dimensions, but since there is not Stretch property, I can't get the image to look right. For instance:

Private Sub Form_Load()

    Picture1.Visible = True
    Picture1.Picture = LoadPicture("c:\myPic.jpg")
    
    widt = Picture1.Width
    higt = Picture1.Height

    newWidt = 1500
    scaler = widt / higt
    newHigt = CInt(1500 / scaler)

    Picture1.Width = newWidt
    Picture1.Height = newHigt
        
    SavePicture Picture1.Image, "c:\temp1\test.jpg "

End Sub

this grabs only the top corner of the image, instead of resizing it correctly....

What's the correct way to do it??

#2
This will eventually have to become a component for ASP. My problem is that it seems that the PictureBox or Image needs the form to exist... simply doing the following:

Dim Pict As PictureBox

Does not allow me to use any of PictureBox's methods... So my question is, how will have to modify this code in order for it to work as a component (without a form..) ??

Thanks very much

dvst8

[Mih_Flyer]

for # 1:
use this

Picture1.PaintPicture MyPicture, Top, Left, Width, Height

it will help u, first thing add the picture to a image and stretch it as you like, then just copy it to the picturebox using PainPicture, it would be something like this:

Picture1.PaintPicture Image1.Picture, 0, 0, Image1.Width, Image1.Height

then save the picturebox.image, Hope this helps.

[HeSaidJoe]

'here is how I would do it...
'load your picture into a picture box that is set to invisible
'save your picture and then load the saved picture into the image
'control.

'One big drawback...VB controls save the picture as a bmp
'regardless of the format of the original picutre..
'
'there is an article on saving jpgs here
' http://vbaccelerator.com/codelib/gfx/vbjpeg.htm

'good luck...


Option Explicit

Const MAX_SIZE = 1500 'Twips

Private Sub Command1_Click()
Dim h As Long
Dim w As Long
Dim pic As StdPicture
On Error GoTo THUMBERR
'Get the picture loaded in picSrc
'or load a picture using the "Open" dialog box
Set pic = picDst.Picture
'Make sure we have a picture
If pic = 0 Then Exit Sub
'Convert the height and width to twips
h = ScaleY(pic.Height, vbHimetric, vbTwips)
w = ScaleX(pic.Width, vbHimetric, vbTwips)
'Scale the destination picturebox to maintain
'the same aspect ratio as original picture
'but have max dimension of MAX_SIZE
With picDst
If w > h Then
.Width = MAX_SIZE
.Height = (h / w) * MAX_SIZE
Else
.Height = MAX_SIZE
.Width = (w / h) * MAX_SIZE
End If
'Clear previous image and picture
.Cls
.Picture = LoadPicture("")
'Scale the picture into the destination picbox
.PaintPicture pic, 0, 0, .Width, .Height, 0, 0, w, h, vbSrcCopy
'Convert the drawn image to the picture
Set .Picture = .Image
'Optionally save with "Save As" dialog box:
SavePicture .Picture, "c:\anewpicture.bmp"
End With
'Clear the pic object
Set pic = Nothing
Set Image1.Picture = LoadPicture("c:\anewpicture.bmp")
Exit Sub
THUMBERR:
MsgBox Err.Description
Err.Clear
End Sub

Private Sub Form_Load()
picDst.Visible = False
picDst.ScaleMode = 1 'Twip
picDst.AutoRedraw = True
End Sub

[dvst8]

nice...

hey thanks for that code wayne! works flawlessly!
resizes the image and saves it in bmp format.... (i'm willing to accept bmp as output of thumbnail)

Question now is, how do I do everything programatically, and not involve the form at all..?
Now, I only know a little about VB, and all that I've done involves objects on forms. No reference book I have read has indicated to me the following: can the object that I embed in a form exist only in code, independent of the form? It seems to me that the answer is no. What I am getting at, is that I need to instantiate a Picture box and use it in my code, without ever having it on the form. Can it be done????

The StdPicture Object seemed like a candidate for me, but it doesn't allow you to set width, height properties...

I was thinking about using StretchBlt... but it needs an input and output device context... I'm not sure what that means.

Many thanks.
dvst8

[HeSaidJoe]

haven't any experience in that field but I've seen'
postings on using sub Main and running apps without a
form...not sure it it was just code or functional objects.

try looking up sub Main and if not post another question..

all the best...and you are welcome for what little I can offer....it's how I learn...looking up stuff for others..