BitmapXres / BitmapYres does not return correct DPI on large files

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This topic and its replies were posted before the current version of LEADTOOLS was released and may no longer be applicable.

#1 Posted : Thursday, April 6, 2006 2:45:58 PM(UTC)

PatriciaT

Groups: Registered
Posts: 2

I'm trying to resize an image to a standard photo size. When the image size is not too big (less than 2000kB), the BitmapXres / BitmapYRes returns the correct DPI so I end up with the correct size and resolution.

However, when the file is large (say more than 4500kB), the BitmapXres / BitmapYres return 72 - which is the default DPI. My picture ends up to be very fuzzy since the original DPI was 300.

Does anyone know how to solve this ?

This is my code snippet:

lQuality = GetCompressionQuality(g_oAppSettings.CompressionQuality)

    Lead1.Load sOriginalFile, 0, 0, 1

    If bResize Then
       If ParseImageSize(lHeight, lWidth, g_oAppSettings.ImageSize) Then
            'convert to pixels
            lWidth = lWidth * Lead1.BitmapXRes
            lHeight = lHeight * Lead1.BitmapYRes
            Lead1.Size lWidth, lHeight, RESIZE_FAVORBLACK_OR_BICUBIC
        End If
    End If

Thanks !!!


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#2 Posted : Monday, April 10, 2006 10:51:35 AM(UTC)

Amin

Groups: Manager, Tech Support
Posts: 367

Was thanked: 1 time(s) in 1 post(s)

Patricia,
To try to identify the source of image quality loss, it would help if I could get the following from you:
1. A sample source image before resizing.
2. The actual values of lWidth and lHeight you pass to the Size method in your code above.

If you want to post an image here, please put it in a ZIP file first. Alternatively, you could send it to support@leadtools.com

Amin Dodin

Senior Support Engineer
LEAD Technologies, Inc.

#3 Posted : Wednesday, April 12, 2006 7:09:07 AM(UTC)

PatriciaT

Groups: Registered
Posts: 2

1/. Attached is a zip file of the image

2/. lWidth = 6, lHeight = 4 (in inches)

Thank you,

Patricia

#4 Posted : Sunday, April 16, 2006 8:51:36 PM(UTC)

Amin

Groups: Manager, Tech Support
Posts: 367

Was thanked: 1 time(s) in 1 post(s)

Patricia,

There doesn't seem to be an attachment with the post. One user in the
past reported losing the attachment when using the 'Preview' button, which might be what happened to you.
Could you please post the ZIP attachment again or send it to support@LEADTOOLS.com?

Amin Dodin

Senior Support Engineer
LEAD Technologies, Inc.

#5 Posted : Thursday, April 20, 2006 4:33:32 AM(UTC)

Maen Hasan

Groups: Registered, Tech Support
Posts: 1,326

Was thanked: 1 time(s) in 1 post(s)

Hello Patricia,

I received your image that you sent to our support department and checked it. I noticed the following:
The file contains the following exif tags:
XResolutin (tag code = 0x011A), value = 0x48/0x01, which is 72
YResolutin (tag code = 0x011B), value = 0x48/0x01, which is 72

This means if any program opens it and does not read the correct tag value, it's a problem in that program.
Other than LEADTOOLS, I checked using Adobe Photoshop and it reads the correct values of 72DPI also.

Please keep me up to date of the status of this issue on your end.

Thanks,
Maen Badwan
LEADTOOLS Technical Support

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