Gimp，python: RuntimeError: pdb.gimp_image_merge_down中的执行错误

Question

我的目标是将一个图像放在另一个图像上，并将结果图像保存为jpeg文件。第一个是新的，它有450x300维和白色背景。第二部分从文件中加载，其可见部分作为一层添加到第一层。

我将以下python脚本添加到/usr/lib/gimp/2.0/插件文件夹中

#!/usr/bin/python
import os

from gimpfu import *
import gimpfu

import logging
def scale(timg, tdrawable, imageName):
    logger = logging.getLogger()
    logger.info('got logo file {0}'.format(imageName))

    newImage = pdb.gimp_image_new(450, 300, RGB)

    newLayer = pdb.gimp_layer_new(newImage, 450, 300, 0, "background", 100.0, NORMAL_MODE)

    pdb.gimp_context_set_background((255, 255, 255))
    pdb.gimp_drawable_fill(newLayer, gimpfu.BACKGROUND_FILL)
    logger.info('Created new background image {0}')
    newImage.add_layer(newLayer, 0)

    timg = pdb.gimp_file_load(imageName, imageName)

    tdraw = pdb.gimp_layer_new_from_visible(timg, newImage, 'logo')      
    newImage.add_layer(tdraw, 1)
    finalLayer = pdb.gimp_image_merge_down(newImage,tdraw,1)
    fileNameNoExt = os.path.splitext(imageName)[0]
    pdb.file_jpeg_save(newImage, finalLayer, fileNameNoExt + '.jpg', fileNameNoExt + '.jpg', 1.0, 0.0, 1, 1, '', 0, 0, 0, 0)

运行通过

gimp --no-interface -b '(python-fu-my RUN-NONINTERACTIVE 0 0 "logo.png")' -b '(gimp-quit 0)'

返回

(gimp:4224)：GLib-关键**：g_error_new_literal:断言‘域!= 0’失败的跟踪(最近一次调用)：文件"/usr/lib/gimp/2.0/python/gimpfu.py"，第821行，在_run返回apply(func，params1:) _run中“/usr/lib/gimp/2.0/plug/my.py”，第31行，按比例finalLayer = pdb.gimp_image_merge_down(newImage，tdraw，1) RuntimeError:执行错误批处理命令经历了一个执行错误:错误：(：1) python的过程执行失败

怎么啦？如何正确地做好这件事，了解问题的根本原因。

编辑。以下是xenoid的建议: 1)使用gimp_image_merge_down会产生白色背景为450,300的logo.jpeg

def my(timg, tdrawable, imageName):
    logger = logging.getLogger()
    logger.info('got logo file {0}'.format(imageName))

    newImage = pdb.gimp_image_new(450, 300, RGB)

    newLayer = pdb.gimp_layer_new(newImage, 450, 300, 0, "background", 100.0, NORMAL_MODE)

    pdb.gimp_context_set_background((255, 255, 255))
    # pdb.gimp_context_set_foreground((255, 255, 255))
    pdb.gimp_drawable_fill(newLayer, gimpfu.BACKGROUND_FILL)
    logger.info('Created new background image {0}')
    newImage.add_layer(newLayer, 0)

    logger.info('loading logo {0}'.format(imageName))
    logo = pdb.gimp_file_load(imageName, imageName)
    # logoDrawable = pdb.gimp_image_get_active_layer(logo)

    #
    visibleLayer = pdb.gimp_layer_new_from_visible(logo, newImage, 'logo')
    newImage.add_layer(visibleLayer, 1)
    mergedL = pdb.gimp_image_merge_down(newImage, newLayer, 0)

    fileNameNoExt = os.path.splitext(imageName)[0]
    pdb.file_jpeg_save(newImage, mergedL, fileNameNoExt + '.jpg', fileNameNoExt + '.jpg', 1.0, 0.0, 1, 1, '', 0, 0, 0, 0)

2)使用newImage.add_layer(visibleLayer，0)以jpg格式存储原始png图像作为输入。

def scale(logo, tdrawable, imageName):
    logger = logging.getLogger()
    logger.info('got logo file {0}'.format(imageName))

    newImage = pdb.gimp_image_new(450, 300, RGB)

    newLayer = pdb.gimp_layer_new(newImage, 450, 300, 0, "background", 100.0, NORMAL_MODE)

    pdb.gimp_context_set_background((255, 255, 255))
    # pdb.gimp_context_set_foreground((255, 255, 255))
    pdb.gimp_drawable_fill(newLayer, gimpfu.BACKGROUND_FILL)
    logger.info('Created new background image {0}')
    newImage.add_layer(newLayer, 0)

    logger.info('loading logo {0}'.format(imageName))
    logo = pdb.gimp_file_load(imageName, imageName)
    # logoDrawable = pdb.gimp_image_get_active_layer(logo)

    #
    visibleLayer = pdb.gimp_layer_new_from_visible(logo, newImage, 'logo')
    newImage.add_layer(visibleLayer, 0)
    # mergedL = pdb.gimp_image_merge_down(newImage, newLayer, 0)

    fileNameNoExt = os.path.splitext(imageName)[0]
    pdb.file_jpeg_save(newImage, visibleLayer, fileNameNoExt + '.jpg', fileNameNoExt + '.jpg', 1.0, 0.0, 1, 1, '', 0, 0, 0, 0)

Answer 1

这是：

tdraw = pdb.gimp_layer_new_from_visible(timg, newImage, 'logo')      
newImage.add_layer(tdraw, 1)

不将图层作为顶部添加，而是在现有的顶层添加。如果它是第二层，那么它就变成了底部层。在这种情况下，merge_down没有什么可合并的。