file-png-save2 Questions

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

GIMP Version: 2.8.16
Operating System: Windows
GIMP Experience: New User

HI，Questions are as follows:
(gimp-layer-scale-full drawable 200 200 TRUE 2)
I scale layer 300 to 200, and then save, but there was a problem,
(file-png-save2 1 image drawable filename filename 0 9 0 0 0 1 1 1 1)
PNG are automatically cropped to the image size of the saved 200, I need it to keep the transparent part of the canvas size does not change
Why the same arguments
(file-png-save2 0 image drawable filename filename 0 9 0 0 0 1 1 1 1)
just click the OK button to save the image using the interactive operations will retain the transparent part, PNG is still 300.why AutoSave may not retain the canvas size?

Wallace · **Posted:** Wed Mar 16, 2016 5:41 pm **(#2)**

I wish I could help you out in some way,
but I have no idea what it is that you're asking.
:puzzled

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

Wallace wrote:

I wish I could help you out in some way,
but I have no idea what it is that you're asking.
:puzzled

HI Wallace thanks for your reply.
I use a screenshot to describe
Did not save to the transparent part the whole picture becomes small.

Attachment:

snip_20160317083056.png [ 877.98 KiB | Viewed 3388 times ]

Attachment:

snip_20160317085808.png [ 629.65 KiB | Viewed 3388 times ]

Attachment:

snip_201603170858.png [ 469.68 KiB | Viewed 3388 times ]

Wallace · **Posted:** Wed Mar 16, 2016 9:57 pm **(#4)**

How did you go about scaling the image?
Have you tried doing "Fit Canvas to Layers" and then export as PNG?

The image below is my Export Image as PNG dialog,
which is showing the default settings.

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

Wallace wrote:

How did you go about scaling the image?
Have you tried doing "Fit Canvas to Layers" and then export as PNG?

The image below is my Export Image as PNG dialog,
which is showing the default settings.
[ Image ]

I didn't do anything, steps as you did above, I would like to have transparent areas 300 pictures is retained,
not 200.

Wallace · **Posted:** Wed Mar 16, 2016 11:20 pm **(#6)**

gimptest wrote:

I didn't do anything,
steps as you did above,
I would like to have transparent areas 300 pictures is retained,
not 200.

Open your image.

Make sure the image has an Alpha Channel

Go to. Layer>Layer Boundary Size

Adjust layer boundary size, center image, click Resize

Go to, Image>Fit Canvas to Layers

Export Image as PNG with these settings

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

Wallace wrote:

gimptest wrote:

I didn't do anything,
steps as you did above,
I would like to have transparent areas 300 pictures is retained,
not 200.

Open your image.

Make sure the image has an Alpha Channel
[ Image ]

Go to. Layer>Layer Boundary Size
[ Image ]

Adjust layer boundary size, center image, click Resize
[ Image ]

Go to, Image>Fit Canvas to Layers
[ Image ]

Export Image as PNG with these settings
[ Image ]

Thanks for your help,I added two lines of code have been successful.

(gimp-layer-add-alpha drawable)

(gimp-image-resize-to-layers image)

Wallace · **Posted:** Thu Mar 17, 2016 12:28 am **(#8)**

gimptest wrote:

Thanks for your help,I added two lines of code have been successful.

(gimp-layer-add-alpha drawable)

(gimp-image-resize-to-layers image)

I hope that what I've shown you,
helped you get to where you wanted to going.

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

gimptest wrote:

GIMP Version: 2.8.16
Operating System: Windows
GIMP Experience: New User

HI，Questions are as follows:
(gimp-layer-scale-full drawable 200 200 TRUE 2)
I scale layer 300 to 200, and then save, but there was a problem,
(file-png-save2 1 image drawable filename filename 0 9 0 0 0 1 1 1 1)
PNG are automatically cropped to the image size of the saved 200, I need it to keep the transparent part of the canvas size does not change
Why the same arguments
(file-png-save2 0 image drawable filename filename 0 9 0 0 0 1 1 1 1)
just click the OK button to save the image using the interactive operations will retain the transparent part, PNG is still 300.why AutoSave may not retain the canvas size?

The API saves a single layer, so the resulting PNG is the size of the layer you saved. When you use the menu, a temporary image is produced by flattening the current image, so the resulting image is the size of the canvas. You may need to use

Code: Select all

(gimp-layer-resize-to-image-size layer)

before saving.

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

Wallace wrote:

gimptest wrote:

Thanks for your help,I added two lines of code have been successful.

(gimp-layer-add-alpha drawable)

(gimp-image-resize-to-layers image)

I hope that what I've shown you,
helped you get to where you wanted to going.

Thank you， very helpful to help me answer.

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

ofnuts wrote:

gimptest wrote:

GIMP Version: 2.8.16
Operating System: Windows
GIMP Experience: New User

HI，Questions are as follows:
(gimp-layer-scale-full drawable 200 200 TRUE 2)
I scale layer 300 to 200, and then save, but there was a problem,
(file-png-save2 1 image drawable filename filename 0 9 0 0 0 1 1 1 1)
PNG are automatically cropped to the image size of the saved 200, I need it to keep the transparent part of the canvas size does not change
Why the same arguments
(file-png-save2 0 image drawable filename filename 0 9 0 0 0 1 1 1 1)
just click the OK button to save the image using the interactive operations will retain the transparent part, PNG is still 300.why AutoSave may not retain the canvas size?

The API saves a single layer, so the resulting PNG is the size of the layer you saved. When you use the menu, a temporary image is produced by flattening the current image, so the resulting image is the size of the canvas. You may need to use

Code: Select all

(gimp-layer-resize-to-image-size layer)

before saving.

Thank you for your reply, use this code solved the problem