ImageMan ActiveX
PNG Image Format

Description

Portable Network Graphics, a bit-mapped graphics format similar to GIF. In fact, PNG was approved as a standard by the World Wide Web consortium to replace GIF. PNG is completely patent and license-free. The most recent versions of Netscape Navigator and Microsoft Internet Explorer now support PNG.

Import Library

im8png.dil

Export Library

 im8xpng.del

Remarks

 ImageMan supports reading and writing 1, 4, 8, 24, and 32 bit images.

Attribute

Read and Write

Name

Data Type

Notes

EXTENSION

String

"PNG"

PNG_COMPRESS

Int8

From 0 to 9, 9 being most compressed

COLORTYPE

Int8

 

Value

Bitdepths supported

0

grayscale

1,2,4,8,16 bit depth

2

RGB

8,16 bit depth

3

RGB palette

1,2,4,8 bit depth

4

grayscale with an alpha channel

8,16 bit depth per channel (converted to 32 bit)

6

RGBA

8,16 bit depth per channel

 

PNG_FILTER

String

"NONE"|"SUB"|"UP"|"AVERAGE"|"PAETH"

Image filter should be used prior to image compression

 

INTERLACE

Boolean

Is the image interlaced for graduated display (browser)

BACKGROUND

Int32

Background color for images with transparency

PNG_cHRM

Binary

Raw Chromacity information

This attribute will be defined as the default value unless specifically defined.

 

PNG_gAMA

Binary

Raw Gamma information

This attribute will be defined as the default value unless specifically defined.

 

PNG_hIST

Binary

Raw Histogram information

This attribute will be defined as the default value unless specifically defined.

 

PNG_sBIT

Binary

Suggested Bit Depth information if images bit depth is greater than needed

This attribute will be defined as the default value unless specifically defined.

 

PNG_tIME

Binary

This is a binary chunk, which ImageMan does not decode or encode, that is Raw Time Date information for image creation

TRANSPARENCY_RGB

Int32

This attribute will be defined as the default value unless specifically defined.

TRANSPARENCY_IDX

Int8

This attribute will be defined as the default value unless specifically defined.

TRANSPARENCY_IDX_ARRAY

Int8  Array

This attribute will be defined as the default value unless specifically defined.

COMMENT

String

SOFTWARE

String

COPYRIGHT

String

AUTHOR

String

SOURCE

String

PNG_tEXt_*

String

Where * is a string identifier of the text field

COMMENT_z

String

Compressed text field that has been converted to plain text

SOFTWARE_z

String

Compressed text field that has been converted to plain text

COPYRIGHT_z

String

Compressed text field that has been converted to plain text

AUTHOR_z

String

Compressed text field that has been converted to plain text

SOURCE_z

String

Compressed text field that has been converted to plain text

PNG_zTXt_*

String

Where * is a string identifier of the text field, Compressed text field that has been converted to plain text

PNG_*

Binary

Where * is a four character field identifier for custom data

 This attribute is not automatically loaded.

 

Read Only

ALPHA

Boolean

The image has an alpha channel if this is set to true. To save an alpha channel the image must have one (16 or 32 bit)

 

 

 


© 2014 Data Techniques, Inc. All rights reserved.

Submit feedback on this topic